[AreaOfEffect]

Wrath Lords can summon 1 ghost a turn.
Werewolves can summon 3 wolves a turn. (Gotten from Call of the Wild)
Mound Fiends can reanimate.

Honestly, I never saw any of the non-unique units-that-make-units make a real difference in a game. At least not by virtue of just making units. Often the opportunity cost of not using them as thugs is way too high.