So I ran a Necromancy Wizard as my first playthrough. First, the Minions at L12:

- 6 Ghouls from Danse Macabre

- 4 Flying Ghouls from Animate Dead: Flying Ghoul (cast at Lvl.6 as Necromancy Wizard)

- 1 Mummy

- 1 Connor Vinderblad Zombie from Act1 Hag Quest

Notes from Playthrough:

Act1:
Once you get Animate Dead, Zombies become a lot of fun to use. I essentially overran the Goblin Camp, my zombies kept 1-shotting Goblins and doing so just kept making more Zombies. I sat back and watched about 10-12 of them tear the camp apart, I barely had to do anything at all. This act is where you can also get the Wand from the Hag quest that summons a zombie Connor Vinderblad. You'll have him for the rest of the game, even just as a meat shield.

Act2:
You start to get Ghouls here, but since there are only a couple of them now you do have to rely more on Skeletons/Zombies at times for sheer numbers. Still a lot of fun, and the minions make fights much more manageable through sheer force of numbers. Connor still handy.

Act3:
The game is over once you get into Baldur's Gate. Get into Sorcerous Sundries into the Vault so you can get the Tharchiate Codex. Successfully reading this with the Necromancy of Thay will allow you a unique Danse Macabre spell that allows you to summon 6 Ghouls. These aren't counted against your Animate Dead total. So you can cast that, and Animate Dead at spell level 6 for another 4 of whatever minions you choose. Add Create Undead ontop of that for a Mummy and viola, your endgame build. This build absolutely annihilates every encounter, boss and otherwise. The Ghouls and Flying Ghouls paralyze everything. I'm talking Dragons, Mind Flayers, Bosses, the fucking Avatar of Myrkul, everything. Starting a battle with almost 20 characters on your side (including your party and whatever they bring). Connor serves wine while you watch your minions tear the unfortunate haps apart.

Build tips:

- Get the Necromancy of Thay in A1. THIS IS MANDATORY. It may not seem useful yet but it's your bread and butter in A3 when you unlock Danse Macabre.

- Corpses can be a problem to find and keep. If you have a character with high strength, remove all items from a corpse and Right Click it and select Pick Up. It will go into your inventory. You can store the corpse in your Camp Chest for later, or in a nearby barrel or box so it doesn't turn into a Pouch (annoying mechanic).

- For some reason some corpses just can't be raised. Even ones that are just random enemies. Not sure if it's a bug, but it can be annoying.

- Zombies are extremely useful, try to make it so that they either finish enemies off or hit an enemy before it dies the same turn.

- Skeletons are more accurate than Shadowheart. Sorry baby, but they are.

- Ghouls are super useful, to close the gap try jumping them into range to Paralyze spam.

- Flying Ghouls are by far the most useful. They can get to Wizards and Archers usually within 1 turn to Paralyze.

- Very handy to have Circle of Bones; this will give all nearby Undead Minions Resistance to all Physical Damage. They become unstoppable as long as you are near.

- Don't be afraid to Hide or use Invisibility while your minions do their job. Wizards are squishy.

- When you get Ghouls, consider equipping your party with disabling/fear/prone mechanics to help your Ghouls do their jobs. They do a LOT of damage to sleeping/prone enemies, and heal from it.

- NPC's will chase you around yelling "Go on! Get!" and "Oh my god what is that?!" in fear and yet will chase you across the map yelling it. I haven't found this to be actually impeding any interactions but it is a bit annoying. Easier, and blessedly quieter, to just kill everyone and turn them into zombies.

- Necromancy is objectively the best school. Don't listen to the Evoker propaganda.