Valkrionn
The Hamster King
Well I definitely have Ashenvale as my State Religion and I've tried losing numerous units on both Attack and Defense; skeletal archers, champions, imps, axemen, and not a single Mane has spawned.
I should have said an LIVING evil unit. Your own units do not give you Manes; Would be even more horrendously unbalanced that way. You could build your own population, one turn a pop point.

I mean, the Scions (undead civ, now in every major FfH modmod) can do that... But their population units are very expensive, and you can't go over the happy cap anyway.