Necromancer deathgrips proc seems pretty rare. I assume the “20% chance on enemy death” is for player kills, but since the pets do all the killing the Spirit hardly spawns.
Black Hand of Sanar’Siin Devourers is on hit
Primal Instinct’s swarmlings are on attack
I see these proc plenty, its very rare to see a spirit. Any other people with pet builds got thoughts on this?
Yes I know this thread is old.
The sad thing is, it’s, for whatever reason, actually intended.
I still think it would be better to give it a little yet important change:
“XX% chance on pet death”
That way it could benefit a pure summoner, and also a hybrid that would also have other summons already, like raise dead for example.
Let alone it would offer a new way of tackling things. Also could effectively counter snapping.
It would be nice to see that the raise spirit scales with player bonus too like raise the death from the devotion to use it with a vitality conjurer maybe.
I play mine with skelletons 
http://www.grimtools.com/calc/4ZD4RpZ7
I would be fine if was on attack instead on enemy death, but the ghosts had to be nerfed because they are rather strong on their own.