I like Edelweiss on a helper, any sort of healing is useful and so is having a second squad that can clear nests.

I'm starting to wonder if the game includes affection and equipment in battle even if it doesn't show it in the power. My 60k helpers feel a lot stronger than my 60k squads... one of them even cleared 12-5 alone. Or maybe total power is not really a good metric for the strength of a squad?