So for a game I'm runnning, I've planned for my party to come upon a haunted battlefield from ancient times. I want them to stumble into a reenactement of the ancient war with a few squadron of ghosts clashing. I don't want to put 60 plus mobs on table. So I stumbled unto the troop subtype and loved what I say. The issue is, I couldn't find any rule on how to build a troop from the get go, like how many hd, ac, damage, etc.
Anyone could help me with that?