Keeping with the firearms references in Super Robot Wars, the Alpha saga features a boatload of examples:
Ingram Prisken's name is derived from Gordon Ingram, an American firearms manufacturer who popularized the MAC-10 and MAC-11 machine pistols.
Astranagant is a composite name formed from the Spanish "Astra" and Belgian "Nagant" firearms manufacturers, respectively.
Viletta Vadim's name is a loose romanization of the Italian firearms manufacturer "Beretta".
Given whom they are clones of, Calico McCready is based on the "Calico Light Weapons Systems", another American firearms manufacturer that specializes in semi-automatic weapons, while Spectra McCready is a reference to the "Spectre M4", an Italian sub-machine gun.
Each "Project TD" Humongous Mecha is named after a heavenly body: "Asterion", "Altair" and "Vega" are stars, while "Hyperion" is one of Saturn's moons.
The attacks belonging to Kukuru's Malgalga are based on the names of the "Imperial Regalia".
Luria Kayitz's name is a reference to the surname of a long-standing rabbinical family in Western Europe.
Keisar Ephes' previous name "Augustus" is a reference to the same-named grand-nephew and adopted son of Julius Caesar, the first and longest-reigning Emperor of The Roman Empire. Furthermore, "Keisar" is a localization of the Roman word "Caesar", a title reserved for Roman emperors, yet it can also be a derivative of the German word or a Significant Anagram of "kaiser", also meaning "emperor", while "Ephes" is "zero" in Hebrew. Mythologically speaking, "zero" denotes a concept of infinity, limitless light and energy and the origin of all.
Unlike the other R-Units, the R-3 is an Expy example: in its stock appearance, it looks like the bare-bones GP-03 Dendrobium Stamen, but once it becomes the R-3 Powered, its configuration closely resembles the Dendrobium Orchis. Furthermore, the GP-03 and R-3 share the same mechanical designer Hajime Katoki, making the similarities apt.
The Shin RyuKoOh is basically a Humongous Mecha version of "Sun Wukong": its extending staff shares the same-named as Wukong's Ruyi Jingu Bang while the Shin RyuKoOh's strongest attack is based on the Celestial cauldron Wukong was placed in after his failed rebellion against Heaven.
The way Machine Cells in Alpha Gaiden are described sounds awfully similar to the "Devil Gundam Cells": both share the same regenerative properties applied to Humongous Mecha in their respective settings.
Each member of Project TD in Alpha 2 (minus Tsugumi Takakura) are an ersatz of a character from Gunbuster:
Ibis Douglas to Noriko Takaya, but without the Gainaxing and not as Hot-Blooded. The analogy to Noriko is taken further when the Hyperion is Banpresto's interpretation of a Real Robot-based Gunbuster.
Meanwhile, compare Ibis to the protagonist of Super Mobile Legend Dinagiga: not only does her Alpha 2 plot mirror the latter, right down to the oddly romantic relationship she has with an amnesiac co-pilot (who is mentally young instead of physically young due to Amnesiac Dissonance), the same white-dimensional-space scene where the Love Interest sacrifices herself to keep the protagonist from killing herself to rescue her is present.
With the amount of haughtiness against the heroine, Ace Pilot skills and talent (plus long, blue hair to boot), Sleigh Presty is a deliberate reference to Kazumi Amano.
Filio Presty to Koichiro "Coach" Ohta: both are the respective mentors to Ibis and Noriko, who entrust the Hyperion and Gunbuster to them because they believe the girls share their level of conviction and determination to accomplish their goals.
Even though it lacks a "GERWALK mode" like the latter, Ibis' Altairlion is similar to the "Variable Fighters" from the Macross franchise: a Transforming Mecha with an aircraft and humanoid configuration designed for deep-space combat, while armed with a multitude of solid-based weaponry such as machine cannons and missiles.
Arado Balanga's basically a more error-prone teenage Expy of Kyosuke Nanbu with a Born Lucky streak; meanwhile, his Wild Würger is similar to Kyosuke's Alt Eisen - both machines are suited for melee-combat, with a similar left-hand mounted machine gun cannon, a unique right-hand mounted weapon (scissors crusher for the Würger, Pile Bunker for the Alt) and can execute an exclusive Combination Attack ("Twin Bird Strike") with a long-ranged, bombardment-based unit.
Like Arado, Seolla Schweizer's essentially a young Excellen Browning Expy, a long-ranged pilot/sniper Ms. Fanservice character who becomes Brainwashed by the enemy. Her Wild Falken has the same attributes as Excellen's Weiss Ritter - suited for long-ranged combat, uses a Swiss Army Gun firing beam- and solid-based rounds and can perform an exclusive Combination Attack with a melee-based unit.
While it has no motorcycle equivalent, the RaiOh and DaiRaiOh are a Homage to the Kamen Rider franchise. In particular, when the DaiRaiOh uses its strongest attack in Alpha 3, its faceplate unlocks to show the machine's facial features, which bears a resemblance to Takeshi Hongo, the original Kamen Rider from the first installment.
If Ryusei Date dodges an enemy attack, he might have a chance at saying "You're ten years too early!", the Catchphrase of Akira Yuki from Virtua Fighter; Ryusei and Akira share the same voice actor.
Levi Tolar's "Judecca" refers to Judas Iscariot, the disciple of Jesus Christ who betrayed him, while each of the Judecca's attacks ("Caina", "Antenora", "Ptolomea" and "Judecca") corresponds to a section of the ninth and lowest circle of hell in "The Divine Comedy".
In-Universe, the "Boxer" was originally going to be the "R-Sword", a separate unit like the R-Gun to be used for the SRX since Alpha, but the idea was scrapped because development for the SRX was nearly complete. Instead, the Boxer ends up relegated as one of two "frames" for the Huckebein MK III to use.
Some of Sanger's techniques are named after certain Super Sentai mecha sword finishers: for instance, his Thrudgelmir's Colossal Blade attack in Alpha Gaiden is named "Inazuma Juuryoku Otoshi", while one of the Dygenguard's techniques in Alpha 2 and Alpha 3 is "Raikougiri".
The Kanaf, Keren and Zanav are based on the Super Sentai team from Taiyou Sentai Sun Vulcan and its Animal Motifs of an eagle, shark and panther. Furthermore, the Nashim and Gebel Gan Eden's respective strongest attacks, "Follow the Sun" and "Catch the Sun", are lyrics from the show's opening.
Cobray Gordon's first Leitmotif in Alpha 3 is "Another Time Diver", a remix of Ingram's "Time Diver"; naturally, this was ForeshadowingThe Reveal of Cobray's true identity. Furthermore, his second Leitmotif, "The Gun of Dis", is a remix of Ingram's "Emissary of the Void"/"Herald of Oblivion" from Alpha.