These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The Roman Legions being able to crush zombie outbreaks for the majority of their reigning period, being Genre Savvy before there was Genre to be Savvy by! And the other best thing about them? They aren't virtually scared by zombies in the slightest-in one tale, an old legion veteran simply pushed a frightened mother and her baby aside and sliced off the zombie's head with his gladius, like it was simply a minor annoyance. They have balls. Of Tempered Titanium.
The Class 4 scenario is especially frightening, as it shows how screwed we really could be if that really happened. The description of the "Total Extinction" scenario is especially chilling. Not to mention the recorded attacks. Worst is the one on the Portuguese Slave Ship.
The Recorded Attacks companion comic manages to illustrate some of the recorded attacks, including the Portuguese slave ship. The incident with the Portugese Slave Ship had a slave ship, with all of the slaves chained in the hold as tightly as possible. A sailor got infected and somehow only bit a few of them. Those ones died and reanimated, but were too constrained to do more than nibble on the guys next to them. 24 hours later, the guy getting nibbled on reanimates. Rinse and repeat. Imagine, for a second, being the guy on the end...
Actually, most of them would've died of thirst long before the infection could be spread along the line that far. More likely, one zombie bit all of them; if its throat was obstructed, e.g. because one of the crew stuck a blade through its neck, it wouldn't be able to feed and would just keep moving from victim to victim.
The concept of "Devil Dance", a game played underground in parts of the French empire in the 17th century. One man enters a pit, armed with a very small knife. In the other side of the pit is one of the undead. Up above, the rich place bets on whether the man lives or, more likely, how long he'll last before being eaten. Most of the zombies used in the game are taken from former players.
Nightmare Retardant: The more you know about biology, weapons, sociology and terrain, the less seriously you take the book.
Paranoia Fuel: If any murder you hear on the news sounds just a bit fishy, get ready.
The whole book makes you think that zombies are real and around the corner.
What an Idiot: The Chinese government's military zombie operation has slight ramifications of this, at least compared to those of Japan and Russia. For example, naming the operation "Eternal Waking Nightmare," the old Chinese name for Solanum. Were they even trying to be secretive about it? At least Japan and Russia used names that only alluded to death ("Cherry Blossom") and long life ("Sturgeon"), respectively.