[Torgon]

No, I already had one lich up and running with another on the way.

And you just loose the 2 crones. That's the point of the swarm cast, keeps them away from your own SC. And two crones are definitely worth the price of most SCs. Really not a whole lot you need them for that mother can't do as well once you have some summons up and running. Mother with a mace can cast all the big nature buffs. Except blessing of Gaia, but just bring along a treant for that. Air or fairy Queens can cast the Air buffs. Once research is done if you can trade a few slow, old, fragile crones for some decked out SC it not a bad trade. Even if you lose a bunch of them in the process.

Definitely not a long term strategy in any way shape of form, but to pull as a surprise move on an unsuspecting opponent dropping a number of SC's on you it can be a rather rude awakening.