Help! My zombies are dying!

They always die no matter what you do :P
I tried many things, running them with hp +ele resist + purity of elements + 20% quality gem + discipline/vitality/determination + neck + mallet + everything and they still die, especially on some bad news boss, it's pretty much insta-rape.
Without necro aegis they're like 50% squishier if not more, i have no idea how their resists are calculated... but i think it sucks.

I tried many things indeed, to make them at least somewhat tanky, if tanky is your aim necro aegis is paramount, lots of hp and resists too.
The only thing i have not tried is Mon'tregul's Grasp, it actually rises their resists and i bet does it differently than stuff like purity of elements or ele resist gem and gives them 2k hp on top, that's pretty damn neat and if anything can make them real tanky it is that mace + necro aegis and perhaps + both determination and discipline auras.

thx :)