As a combat vet, this is why I thought Apocalypse Now despite all it's sureality, was one of the most realistic war movies ever made. It captured the unbelievable, upside down insanity of war.
I cannot claim to be a vet. Even so, Apocalypse Now is one of my favorite movies (despite Martin Sheen). When people ask me why, I tell them it seems to not be so much of a war movie as a psycology of war movie. My brother, who is a Vietnam Vet, was amazed that I thought A.Now was a great movie (not that he didn't). Great comparison with Liberia.
So far as capturing the wierdness and irony, you're spot-on. The inaccuracy results when, for the storytelling's sake, they compress all the oddities of a tear-long tour or career experience into a couple of days, making them into a routine happening.
I did indeed see more than a few wild-o things take place, and heard of quite a few more. But for the most part, we recognized them at the time as abberations, and not the usual way things were, or should be.
It's when such things frequently take place and aren't recognized as unusual that your sanity begins to suffer.
And I swear, those stories about frequent cannibalism were untrue, despite the Cambodian bodies with the livers missing. Most of the stories, anyway.
-archy-/-