I’d recommend Summon Creature as the focus of an Attack preventing Necromancer as you described it towards the end, both because of the increased disposability and the absence of commanding issues.
Of course this limits the number of minions you can have, so I understand wanting to go with permanent minions (that can also run your coffee-themed dungeon).
Time is an issue however, because your minions won’t be too strong (though stronger than mere Summons), are essentially used as cannon fodder and you can only create one per day, even less if you’re in a travelling group and later on want to permanently Dominate each of them.
For this, the obvious solution is Boon Focus II (Animation), which, though costly, drastically increases the speed of minion creation.
An interesting approach to controlling your minions could also be using an Extraordinary Item I designed, in this case using a lower PL Dominated:
This obviously requires Craft Extraordinary Item (note that it requires you to be the crafter intentionally), but Heightened Invocation could be dropped instead. A nice side effect is the increased versatility you get from it.
This might seem to go against my previous time concern because crafting one such crystal takes longer than permanently Dominating a minion, but consider this:
With an Animation build, you’re going for the long game. If one of your permanently Dominated minions dies, that is a lot of lost time you cannot recover (unless your GM allows you to resurrect it via another Animation with the Bane intact, but don’t count on it). If you’ve stuck one of the crystals into its chest, you can likely recover it.
This also empowers the GM somewhat as they can craft interesting story elements and balance the game by occasionally shattering a crystal from an Attack or stopping them from working in an area. I argue that is a good thing, as it makes the story interesting and increases the chance to be allowed by the GM.
Addendum:
Additionally, the Crystal of Control is accessible sooner than Heightened Invocation III. In fact, at WL2 for Cursed (Dominated 5) (or maybe WL3 if the GM deems it powerful enough to increase its WL), it’s accessible as soon as you take Craft Extraordinary Item.
EDIT:
I remembered Heightened Invocation wrong, which needs 5 days to permanently Dominate a minion. Crafting a Crystal of Control for a minion at WL2 requires only 4 days and is therefore the better way all together.