Couple things that popped out:
- EHP is very low, and a lack of defensive layers
- No flat damage for minions from weapon.
- No Critical Strike Avoidance
- No Dread Shade
Since you chose necromancer I would recommend putting a golem and dread shade to get the most out of the mastery. Dread Shade is going to immensely boost your minion’s damage with an additional 12 flat necrotic damage as well as a 30% increased attack/cast speed.
Golem has a few functions like hunger which grant you some leeched life and they can also pull aggro which is going to make your runs feel a lot smoother.
Switch Cling to Life to Tyrant, that should help you start get build up your HP.
Skeletal Mage doesn’t need Leech Life as the mages will sustain themselves off of critical strikes via River of Bones/Grey Merchant. Moonlight Pyre will give an additional 10 flat necrotic damage. You are severely lacking in flat damage and once you get more you’ll notice a big boost in clear speed.
EDIT: Ribbons of Blood might be very useful since you’re running mainly melee minions.
Necrotic Penetration won’t shine if your base damage is lacking.
Your defenses are lacking as well. Capping your resistances is a bare minimum and entering Empowered Monos means that you’re going to want at minimum 2k hp. You are getting one-shotted because you have very low EHP. If you’re going HP route than you’ll need to get some more armor. Capped Critical avoidance is going to prevent a lot of oneshots as well.
You can also go low-life route and build ward which is something Necromancers do very well and there are lots of different passives nodes that help build ward. I find it’s way easier to build for ward than HP for necromancers.
Here’s Boardman21’s necrotic melee build that looks similar to what you are going for.
Damned-Necrotic-Melee-Minions-Build