Prophet and pretender spread dominion similar to temples; preaching only affects the priest's province, however, and most priestly commanders are non-stealthy.
Inquisitors, incidentally, are better at tearing down local enemy dominion by preaching than are normal priests; and everybody's a more effective preacher with a local temple.
Skeptics (EA Arcosephale) are stealthy and reduce dominion (anybody's) where they are; Stone Idols have a similar effect. Melancholia is one spell which reduces dominion in the targeted province. If memory serves, at least one of the Demon Lords also reduces dominion... but, IIRC, none are stealthy, so you need to control the province first.
Theoretically, a Skeptic Prophet with a Stone Idol and the Ark should be one monster dominion-shifter.
There's also Wish, but that may not be the most efficient use of 100 pearls.
EDIT(addition): There's another reason to build temples -- you need one to be able to recruit sacred units or commanders.