The black faction's abilities don't affect the Hive, only Fist does! And to level up Summoning just for the Hive's special ability, I don't know... Phoenix is good, but Elves have problems with spell power!
It's clear that it's not worth leveling up for the Necropolis just for the Hive. I'm just surprised by some of the spells in the game. For example, Minefield, Wall of Fire, and Confusion, or whatever it's called. The only time I appreciated Confusion was when some mega-wizard cast it massively. My archers refused to shoot, and the druids refused to cast spells. And no matter how many times I cast it myself, it had no effect.