The gear looks barely acceptable. You could upgrade armor to Smoke(Nef+Lum). Next, the amulet, at this stage it’s very easy to gamble +1 All Necromancer skills, or +2 Summons tree. For shield you have options - Splendor(Eth+Lum) in a shrunken head for cheapest possible +1 All skills, faster cast rate and decent magic find; Ancient’s Pledge(Ral+Ort+Tal) for massive all resistances, sadly can’t be created in shrunken head; or Rhyme, no +All skills, worse resistances than Ancient’s Pledge, but has cannot be frozen, mana regeneration and a bit of magic find. Belt is also something which could use an upgrade. Your boots are pretty good though.
For the merc, replacing Impaler with Insight, as Rondel pointed, will make your life waay easier thanks to mana regeneration - and Corpse Explosion, which is main damage dealer is rather expensive.
The last piece of gear which will immensely help is staff with Teleport charges on 2nd weapon slot; using it you can reposition your army, and preforming teleport on an enemy(you point him with a cursor then teleport onto him) you’ll cause ALL your minions immediately start to attack the chosen enemy, without having to surround him.
Skill distribution however…that’s where you could make some adjustment.
1st, 20 points in Clay Golem is a waste, the guy even with so much investment won’t do much damage. It’s core role is to slow enemies, and to do that 1 point +All skills stuff is enough.
2nd, lv4 Corpse Explosion has just 3.6 yards radius; that’s more or less like waypoint circle, laughable at best.
3rd, same for Amplify Damage, at this level it just does too little to be really viable.
4th, Skeletal Mages are not worth investment other than being prerequisite for Revive.
Consider such changes; btw, by clicking shield slot then choosing All items>Left Hand you’ll see Rhyme, Splendor and Ancient’s Pledge, and you’ll be able to change the shield to see how stats change.
About abilities - by removing 19 points from Clay Golem, and 3 from Skeleton Mage I was able to raise level of Corpse Explosion and Amplify Damage to make them have some reasonable range. Spare points I’ve put into:
- Decrepify - wonderful curse against bosses/tougher enemies, its slowing effects adds to that provided by Clay Golem.
- Bone Armor - because it’s good to have a point there so +All skills equipment can raise it, and extra protection against
- Summon Resists - minions don’t have resistance penalty in Hell difficulty, but having 0 resistances they won’t last long. Just one point gives them +44% all resists.