The "Mille", the thousand-something volunteers that followed Giuseppe Garibaldi on his expedition to conquer the Kingdom of Two Sicilies and unify Italy in 1860. The youngest was 10 years old. The oldest, 70-something. There were students, poets, shopkeepers, tailors, pharmacists, bakers, former soldiers and officers of the regular army, medics, pretty much anything, including a woman, each with his own motive: fame, fortune, romance, adventure, ideals, death (reportedly one of the volunteers jumped offboard the ship twice during the trip to the shores of Sicily). They wore civilian clothing that only had in common the color red (the closest thing they had to an uniform) and were armed with old rifles obtained by tricking an army quartermaster into giving them. Besides, the rifles themselves never saw much use, since Garibaldi's tactical philosophy was "the rifle is nothing more than the grip of the bayonet". And apparently it worked, as they eventually conquered the Kingdom of the Two Sicilies.
This always was Garibaldi's Modus Operandi: find a big country, assemble a ragtag bunch of misfits, and go kick asses. Sometimes, Garibaldi's troops were fighting long after the rest of the country they were fighting for had been crushed: during the Uruguayan civil war, the regular Uruguayan forces were crushed at the battle of Arroyo Grande: Garibaldi's ragtag bunch of former slaves and immigrants held the city for nine years and eventually won the war.
Garibaldi was helped by two factors: first, his foes tended to think that time he had bitten off more than he could chew and didn't take him seriously for a while; by the time they realized he could actually do it, their army had lost morale and his own had grown, partly thanks to defections from his enemy. The Mille are a good example of this: when they landed in Sicily proper there was about a thousand of them and were regularly faced by similar-sized forces, when they landed on the continental part of the kingdom after conquering Sicily there were twenty thousands of them and had much better equipment than at the start, and by the time of the final battle they were thirty-five thousands, most of which having deserted the Sicilian army during the campaign. That's why the Italian army (that would usually stick him at a place they wanted conquered and wait 'till his 'unexpected' success gave them an excuse to intervene) and the French army (who had already fought him once and got their collective asses kicked hard) managed to defeat him: at the Aspromonte (Italians) and Mentana (French) they attacked him with their best troops in superior numbers, either forcing him to back down (Aspromonte) or utterly defeating him (Mentana).
The ships that ended up discovering the Americas originally had an overwhelming majority of criminals and other lowlifes as their crews, as they weren't even expected to make it through alive, let alone come back. (Predictably, malnutrition and illnesses did end up mowing a lot of them down on the way.) This also partly explains the horrible treatment the natives suffered.
Hollywood History example: According to widespread belief (and would Hollywood lie to you?), the Americans were the Ragtag Bunch of Misfits who drove the British from their shores during the American Revolution. In history, of course, the Americans did form proper military units, with ranks and rules and discipline and everything. They did do so with a lot of foreign (especially French and Prussian) help, but...
General 'Von' Steuben took advantage of the long winter at Valley Forge to whip the Continental Army into some kind of shape. A lot of the Founding Fathers were emotionally and ideologically committed to the 'citizen soldier' ideal. George Washington, who for his sins, had commanded militia men in the French and Indian War knew that this was unworkable. Not because citizen soldiers are cowards but because it takes training and discipline to make men do something as counter-intuitive as stand still and let the enemy empty their muskets into them.
Modern researchers on the battles of Lexington and Concord have concluded that the Massachusetts Militia actually contained a higher percentage of combat veterans from the French and Indian war than the so-called professional soldiers they opposed. Which probably shouldn't surprise anyone, considering that they managed to pull off a seven mile moving envelopment. One British Officer writing home after the battle concluded "These people know very much what they are about."
Gen. George S. Patton, when taking control of the US armed forces in Africa, started by levying heavy fines for soldiers and especially officers for unkempt uniforms. By the time Patton engaged in the famed 609 Battle, he'd transformed, well, you-know-whats into bonded soldiers.
Another example of "folk history", this time Russian, is the Red Army, which, according to popular belief, drove out the White Army with pure revolutionary enthusiasm during the Russian Civil War. While it was a ragtag bunch for a short time since its creation, it was completely unsuited for combat, and only began to score victories against the Whites after its transformation into an actual army, with ranks and discipline — mostly courtesy of former war specialists from the disbanded Tsarist army, whom the Bolsheviks began to enlist after realizing that the "army of workers and peasants" ideal didn't work at all.
The reorganization of the Red Army was supervised by Leon Trotsky. Trotsky became the ultimate persona non grata during Stalin's rule, which may help to explain where the popular belief came from. Stalinist history textbooks obviously couldn't talk about Trotsky's role in building the Red Army, let alone the role of counterrevolutionary officers from the Tsarist period.
Speaking of the Russian Red Army, The 1980 Winter Olympics featured the Soviet Hockey juggernaut playing against a bunch of college hockey players who just happened to be playing for the United States. In what would become known as the Miracle on Ice, the college kids toppled the Russians 4-3, with a little help from the home crowd. Canada did it first, eight years earlier, with an All-Star lineup of NHL players - many of them future Hall of Famers - and in an exhibition series, not the Olympics. The Americans? Over a third of the team, including the captain, never played a minute in the NHL.
Real world example: grab a book about Mexican history, open it on the chapters about the 19th century and the Revolution, and you'll see at least five disorganized bands duking it out for any reason. In fact, the reason why the Cinco de Mayo is a national holiday is because that was the day when a ragtag bunch, led by Ignacio Zaragoza, kicked the crap out of the disciplined and well-equipped French invaders. Puebla was lost a year later but after too much complication the liberals won the war and completely squashed the competition, this time permanently. (That doesn't mean other conflicts appeared but...)
The Texans who won their independence from Mexico were mostly ranchers, farmers, brigands, and failed American politicians, but some of them (mostly officers) had some military experience. Some even Mexicans as Lorenzo de Zavala.
The violent Indian Freedom Fighters who fought the British were very much this. Although their role in securing Independence was fairly minor, Britain simply didn't have the resources to maintain its empire after World War II, not to mention it had very much lost the High Moral ground to Gandhi.
The Calcutta Light Horse were less a ragtag bunch of misfits and more a bunch of expatriate English barflies, but they did manage to infiltrate Portuguese Goa during World War II and destroy an interned German merchant ship passing radio intelligence out of neutral territory.
The Battle of New Orleans at the end of the war of 1812 was basically won by one very good leader (Andrew Jackson) with a ragtag bunch of misfits. And pirates!
Wimbeldon FC's "Crazy Gang," with a reputation for pulling an assortment of practical jokes on each other and their manager as well as for playing The Beautiful Game with a very unsophisticated and amateurish style, were able to beat the much more skilled Liverpool squad in the 1988 FA Cup Final against all expectations.
Then there’s Jesus himself, a small-town guy who worked construction for a living, got dissed on for his country accent when he went to the big city, and never was accepted in his home town, at least partly because of his dubious parentage (of course, nobody believed Mary when she told them who the daddy was). Even away from home he was unjustly accused by pious folks of being a drunken party boy because of the “tax-collectors and sinners” he hung around with.
The French Foreign Legion, at least according to all those romantic novelists...
Their recruitment still is "unconventional", but there is a pretty strict selection process with a psychological evaluation, physical and medical tests and even a test of logic and mental abilities. After that the soldiers receive just as much training as in any normal infantry unit. The basic contracts last for 5 years, and they are deployed regularly (Wikipedia list 5 current missions as per December 2008). So while practically everyone there is some sort of "failure" looking for a second chance, they are much better trained and organized than any movie bunch.
The Crusaders, especially during the First Crusade. Runaway serfs, criminals promised a pardon for partaking crusade, disinherited younger sons, miscellaneous adventurers and ribauds, who marched through Europe in order to conquer the Holy Land. Surprisingly, after an initial defeat, they are joined by an army of real professional soldiers - the Crusader Knights - which then go together to conquer Palestine and found the Kingdom of Jerusalem.
Israel actually subverts this trope by taking these misfits, and organizing them into settlers and soldiers. They started out as misfits, but due to the unifying and organizing force that was the Zionist movement quickly lost that designation. Most of the country's accomplishments are due to having its Misfit Mobilization Moment very early, and most importantly, before getting involved in any war. Against the expectations of every single military power in the world, said ragtag group beat back the well-equipped Arab Armies, who collectively had as much manpower as Israel had people, including the massive elderly Jewish population of Jerusalem.
Casting the British Mandatory occupation as the Obstructive Bureaucrats at best, and with many of the companion tropes and ideas such as
improvised weaponry such as catapults for explosives, canes with a single bullet for the elderly, and an "air force" consisting of tossing grenades out of Cessnas
Refuge in Audacity such as claiming to have nukes in 1948, stealing electricity from the British to power the literal underground bullet factories, and so on.
The Norwegian resistance movement during World War II fits the trope, as the many groups involved developed locally, and didn't have a chance to communicate with the Norwegian exile government for quite some time. Meanwhile, the different groups seemed to step on each other's toes. And yes, they were mostly ordinary guys without proper combat experience, and homemade tools that didn't go off as planned. AND there was the communist faction, who did not communicate well with the others.
The Haitian slaves owned by France back in the Napoleonic days could be counted on to fight, argue, and fight some more. With the help of Toussaint Louverture, they managed to stop bickering long enough to kick the French's ass. Tragically, they went right back to the whole Ragtag misfit thing, and the country has languished in the third world as a result.
Averted by the Canadian rebellions led by William Lyon Mackenzie in Upper Canada (later Ontario) and Louis-Joseph Papineau in Lower Canada (later Quebec), who were both rebelling against the nepotism and corruption of the British colonial governments of the time. Papineau and Mackenzie's "soldiers", if you could call them that, were mostly common farmers and labourers who were poorly trained and disciplined. Needless to say, the trained British troops mopped the floor with them, but at least the rebels eventually got the political reforms they wanted after the fighting ended.
Bolivar's army was a subversion at first (to put it simple: everybody wanted to be the leader by having indy ploys every three seconds instead of the ones they were planning for months before...), since they spent around twenty years of 'we did it!...oh, sorry, the Spanish beated us again...' before deciding it was easier to free Colombia and then, with the support of a whole nation, get Venezuela free. It worked.
NFL example: If documentaries by NFL Films (such as the America's Game series) are anything to go by, the Oakland/Los Angeles Raiders are likely a good example of this, at least the teams from the 70s and 80s under head coaches John Madden and Tom Flores. Featuring many castoffs from other NFL teams, players who were considered washed up, and some colorful personalities with chips on their shoulders, the Raiders were a bunch of misfits who became the "bad guys" of the NFL because of their highly aggressive play (especially players like George Atkinson and Jack Tatum). They were also a successful bunch of misfits, winning Super Bowls XI, XV, and XVIII.
Outcasts United by Warren St. John is a real life example of this. It is the story of a bunch of refugees who ended up living in Clarkston, Georgia (a small suburb of Atlanta), which became a resettlement center for refugees from war zones in Liberia, Congo, Sudan, Iraq and Afghanistan. These kids eventually start a soccer team, the Fugees, with the help of Luma Mufleh, an American educated Jordanian woman. It the prejudice they endured and the money struggles they have, and the culture clashes (such as how in Georgia soccer is a sport associated with rich people).
The rebels in the Libyan Civil war. Very few of them were actual soldiers.
The Oakland Athletics in the early 2000s, as seen in the book and film Moneyball, were deliberately assembled as a championship team that the club could actually afford. This entailed culling players from "the Island of Misfit Toys", standouts in one area who flounder in others. A classic example of this was Scott Hatteberg — where most of baseball saw a catcher with an injury that prevented him from throwing the ball, the A's saw a batter with a preternatural ability to avoid getting an out (and whose arm injury wouldn't matter if they put him at first base instead).
Many of the NHL's "Cinderella" teams can be described as this. The 2003/2004 Calgary Flames and 2005/2006 Edmonton Oilers could be best described as a group of talentless players (minus one or two) that played their hearts out, sacrificing their bodies to outplay everyone. By the time the dust settled, the teams had little, if any, players healthy enough to play the last games of the playoffs.
The 2011 Arizona Diamondbacks were branded this by the media. While the 2001 World Series team feature a group of proven veterans, the 2011 team featured only Justin Upton as the only star. But coming off a miserable 2010 they managed to grab two pitchers for players of lesser value. They also featured a pitcher that throws a baseball like a tomahawk and the player with the most tattoos in the majors. They managed to unseat the 2010 Giants as division champions, against them no less before losing in the first round of the playoffs.
Reddit and 4chan's /v/ board had a competition in Tribes: Ascend. Team Reddit was a well-coordinated, heavily practiced team with high-end computers; Team 4chan was a hastily-gathered team of /v/irgins run by a furry with a tripcode and a Brazilian sniper with 140 ping playing on toasters. 4chan won 3-2.
"WE WINNERS NOW"
The army of Chad counts as this in the Toyota War it fought against Libya in the late 1980s. Chad's army was a cobbled-together alliance of rebel and government forces who until very recently had been at each others' throats, was outnumbered and outgunned by their Libyan opponents, and was so underequipped that it had to use Toyota transport trucks to ferry its troops. Despite this, they still managed to win against the Libyans, in no small part because Muammar Gaddafi was a cross between a Modern Major General and a General Failure.
The British Army lives and dies by this trope. One of the first modern armies, the New Model Army was a complete subversion (English, but the framework for the British army was laid here), made up primarily of professional soldiers who had been fighting against the Royalists...until they were only able to fill about two thirds of places. After which, the Army lowered its standards. From then on, to about 1914, the Army was been considered the second service to the far more prestigious and skilled Navy (the "senior service"), taking on colossal numbers of thieves, rapists, murderers and arsonists, then moving on to those who have failed their GCSEs. This trope was so prevalent during the Napoleonic Era that the Duke of Wellington noted how wonderful it was to make so much of them. This applies less to other armies as they tended to still take Peasant Levies, meaning the men were required to serve whatever their profession, or have a very elite air and esprit de corps (the French, up until 1812).
The Fourteenth Army of WWII, in particular, was the last great colonial army, a massive Multinational Team described as "the scrapings of the barrel." It operated on a shoestring, often using obsolete equipment that other theaters no longer needed and devising local solutions for things it couldn't get. Its predecessor, Burma Corps, was even worse off. It was composed of the newbie and ill-equipped 17th Indian Division, the even more newbie and worse-equipped 1st Burma Division, and the experienced 7th Armoured Brigade of the Desert Rats — supported by the unreliable and completely unequipped Chinese, and the mercenary American Flying Tigers. Incredibly, it retreated from Burma intact under the leadership of Bill Slim.
For the effects George Lucas wanted for Star Wars: A New Hope, supervisor John Dykstra assembled some college students, artists and engineer to create Industrial Light and Magic. In their large empty warehouse, they wound up wasting $1 million (lots of miniatures and technology were created, but the only scene they made that could be salvaged was the Tantive IV's escape pod being released, which even opened the Star Wars trailer) and had an unorthodox working environment that shocked 20th Century Fox executives when they visited. Once Lucas returned from the already-screwed enough shoot in England, he put the motley crew of technicians under a tight leash to make sure the effects were made... but not before he was hospitalized in shock.
The East African Schutztruppe of WWI was held together by the personality of its commander, Paul von Lettow-Vorbeck. Part African soldiers, part Arabic auxiliaries, part African civilian carriers and their families, part Prussian officers, part German civilian settlers, and part Naval survivors of the raider Konigsburg, it was the last German force to surrender - having invaded the Congo, Mozambique and Rhodesia first.