I am currently in book 2 and right before be storm the keep I ended up thinking of a name for my guy's crusader army.
The speech he gave before they left Kenabres ended with my Empyreal knight saying "The Wardstones are not gone. We are the Wardstones and this is the Last Crusade!"
So right before the battle a new banner was unfurled and he named his army "The Wardstone Legion".
The mercenary army we picked up ended up naming themselves the "Guardians of Paradise."
What did you guys name your armies?