Summonancers are generally effective at all levels. From my experience, their main challenges are:
- Weak against act bosses early on.
- No teleport.
For point 2, get 55% Faster Run Walk and buy a teleport staff from Akara. It’s not as good as the Sorc, but it helps.
Regarding point 1, starting out, my skellies could hold their own in normal act 4 but then get absolutely shredded by Diablo, which caused me to have to go back to Act 1 to raise another army quite a few times. This was a bit frustrating…
My struggle against bosses continued all the way through Hell. I solo’d all of them, even Hell Baal, but it was a challenge to keep my army alive.
Now, my summonancer is extremely stout and can kill Hell Diablo and Hell Baal with ease.
What caused it to get easier? I found/traded for better items to push Raise Skeleton and Skeleton Mastery as far as possible. Here’s what I used with good success:
Spirit sword
Spirit shield
Staff with Teleport charges on swap
Stealskull Helm for MF (I replaced it with a Shako)
Trang Armor with +2 Summoning Skill and 40% FRW
Rare Belt with +life and Resists
Rare Gloves with MF and resists
Marrow Walk Boots with +2 Skeleton mastery (self found)
Rare +1 Skills Necro amulet with MF (just replaced with a 30 Mara’s that I found in CS)
Nagel Ring with 30 MF
Rare Ring with +mana, resists, and MF
Hellfire Torch
Inventory with resist and life charms (not the greatest, but it helps)
Also, my merc has a Colossus Voulge Insight. He hits pretty hard.
With the above gear, I do well enough and can handle everything.
Back to your questions, summoners get good when Raise Skeleton and Skeleton Mastery are maxed, so focus your points on them. Also, put just 1 point into Mages and 1 point into Revive. 1 point, Visiley, 1 point only.
Regarding the Shaman question and targeting, no, you can’t have your minions target a mob. The answer you seek without knowing it is Corpse Explosion. Max out this skill. It can have insane range at higher levels. When your skellies kill one of the little demons, Corpse Explode them to kill everything around them. This can lead to a chain of Corpse Explosions and soon the whole screen is dead including the Shamans. Max Corpse Explosion.
Also, make sure you use your curses. My go to curses are Confuse, Amplify Damage, and Decrepify.
Confuse agros mobs which helps with clear speed. It also takes the heat of your army
Amp Damage doubles you Army’s damage and increases Corpse Explosion damage by 1.5x (CE does 50% physical and 50% fire danage).
Decrepify slows enemies which helps your army’s survivability. It also increases damage by a bit. I use Decrepify against strong enemies like Minions of Destruction. Once one dies, I cast Amp Damage on the mobs and then corpse explode them all.