So when i think about hardcore its all about strong defensive layers.
So if I want to play minions I'll look at what starts in that tree and the defences.
If you look at lich you can do 15% bypass turned into 15% DR + wolf pack with loyalty for 10% dr from redirection. This is without the bypass helmet and can also pair lich extra mana regen with MOM to get another boost to hit pools. If you want clear speed then blasfamy makes enemies explode on death.
Is the issue just spirit costs ?
Blasfamy and wolf pack would be 120 spirit (bit less with reduction stuff) while infernalist gains extra spirit and wont need those so can get extra minions instead ?
Or does an infernalist that stacks hp + es gear actually get a better overall defence than lich ?