I have a level 90 zookeeper, and the build is certainly viable. He only died once on hell difficulty (so far), and that was when he was about level 58 attacking an LEB in the monastery, with no minions left and negative lightning resist.
The only things that were really difficult were specters for some reason.
Two things that help: he has items that add +15 to the summoning skill tree, and he has enough mana to cast high level bone spirits continuously, even with fast cast.
I can recommend a thorns mercenary and a fire golem. I would not recommend an iron golem, because I believe the thorns do not add together. Someone please correct me on that if I am wrong. Also, he has about twenty skill points in reserve for when the patch comes out.
None of the minions do a whole lot of damage, except the hireling. The mages will eventually kill things if you are very patient. However it is very difficult for most monsters to get to you through forty something cold bodies (I almost wrote "warm bodies" but that is not the case). A high level skeleton will take more than a couple hits, and the mages last quite well. When my necromancer defeated baal for the hell quest, there were two mages and one revived death lord with him at the end.
(edit: I can't spell.)
The only things that were really difficult were specters for some reason.
Two things that help: he has items that add +15 to the summoning skill tree, and he has enough mana to cast high level bone spirits continuously, even with fast cast.
I can recommend a thorns mercenary and a fire golem. I would not recommend an iron golem, because I believe the thorns do not add together. Someone please correct me on that if I am wrong. Also, he has about twenty skill points in reserve for when the patch comes out.
None of the minions do a whole lot of damage, except the hireling. The mages will eventually kill things if you are very patient. However it is very difficult for most monsters to get to you through forty something cold bodies (I almost wrote "warm bodies" but that is not the case). A high level skeleton will take more than a couple hits, and the mages last quite well. When my necromancer defeated baal for the hell quest, there were two mages and one revived death lord with him at the end.
(edit: I can't spell.)