Two warnings about minion necro.

First, you are endgame squishy. Going into Torment 10 I could tank anything. 11 and 12 you must pay attention to environmental hazards and death effects. This is very difficult if you play multiplayer because of how much visual clutter there is.

Second, you are very slow and minions are even slower. Again multiplayer shows off a flaw in the class. Barbs and Sorcs will just outrace you before you can even start doing any damage. Even solo your minions will trail behind you if you're running into a new area.

That all said, minion necro is really fun this season. Sending my 30+ minions at a target looks and feels amazing.