I don't think magic scales affect Reanimate, only the reanimator's priestly level. Undead priests are also slightly better at reanimating (they count as having +1 Holy level for the purpose of determining what kind of undead they can raise).
The only way dominion affects Reanimate is that you get 15% chance per candle to raise an additional unit, and that bonus doesn't apply to the beefier reanimations, like Tomb Wyrms or Lictors.
Corpses in the province only affects the Reanimate Soulless order and a handful of soulless-generating spells.
Ghouls, Longdead, Longdead Horsemen, Lictors will all be produced at the same rate no matter how many corpses there are or aren't in the province. OTOH, Reanimate Soulless will produce up to 4 times as many individual undead than them, corpses providing. Those soul less will also likely come with some equipment, or be of the type that produced the corpses in the first place (for example, fight Atlantis and you might get atlantean zombies in coral armour)
Without corpses, Reanimate Soulless is worse than Reanimate Longdead in most respects.
The same is true of the battle spells Animate Dead / Animate Skeletons BTW: Animate Skeletons are consistent, whereas Animate Dead will get better once soldiers have begun dying on either side (but only live ones - undead or constructs don't produce corpses).
More thorough analysis
here.
Re: ERMOR newbye questions
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