Which characters would you want to find in an erotic romance set in World War I, that also happens to have werewolves?
You forgot this one!
[edited to add, answering comments]
The nurse could easily be a werewolf, given my Grand Theory of the Werewolves in This Book.
Ooh, Russians! Ooh, French artistocrats! Ooh, prisoners!
The Amusing Rake could either start out shell-shocked or gets that way. Also the officer-in-love-with-the-poet, particular if young and pretty.