[Agema]

I think Jim's right that priests can raise a province above their theoretical maximum. Presumably the game is letting them all check based on the initial dom, rather than checking one by one and stopping when the max is reached. I've not tested this, just thought so anecdotally.

I'd see temple dominion as a spreading plant, like kudzu. You don't really control it much, it goes creeps dominion along everywhere. The advantages of friendly Dom are listed above by others, and hence you might view some provinces as "key" ones that it's best to convert quickly. My suggestion is letting your temples do the generalised advance, whilst having one or two "firefighting" squads of H2/H3 (H1 if you've nothing better) priests to work on key provinces where necessary.