Quote Originally Posted by dismal
That's what I would think as well. That's a lot of time and money to devote to changing a town's religion. Seems you could march in and take the town directly for less.
Two words: Religious unrest.
I dont like having to march in to a city only to have it (at worst) rebel in two turns because the religion was way different than mine. And I dont like having to spend five turns just trying to get the garrison and buildings needed just to prevent civil strife. With a zerg rush of generals, you can march in the land, wait a turn while the enemy deals with strife of his own due to your religious conversions, send an assassin in to burn the temple or church to further this action, and then assault next turn, build one garrison unit, and move out and move on. Definately quicker than just marching in and taking over.
You can also use this method to conquer without going to war. Just use assassins (to destroy the happiness buildings and temples), generals, and spies until the city turns rebel, then move in. And thus was born a new player-restricted challenge: winning without ever declaring war.