Does it exist?
 

This may seem like a weird question, but is there a creature which summons allies (like a mictlan chief or werewolf) or spawns troops pssively (like a Pan or Vampire Count) which creates troopers that exist only in the ancient era?

The ability to make a creature that summons allies with the mod commands doesn't exist, but you can copystats a creature that can do that and then mod the creature it summons into something you want. But I can't think of anything that summons that I can mod into the Middle or Late eras that wouldn't cause harm elsewhere.

-Frank