Favor, as a special and very powerful resource, is capped at a 100. Players are not meant to hoard favor and build masses of Giants with the expensive Great Big Dirty Club upgrade, sned them into a town, call for 50 simultaneous god powers, and cause general chaos in a few seconds. But, in the late game, Greeks can send their entire vill population to pray at temples and pratically instantly regenerate their favor. As favor never "runs out", this could be a serious balance problem.
Thus, I suggest that favor should be like Starcraft's Vespene gas: only a limited number of villagers can effectively pray at a given temple at a given time. If temples are pricey in wood, gold AND perhaps favor, then one can' accumulate favor rapidly.
Not all old men in ragged coats are bad old men; some are bone-and-bottle men, and have little dogs of their own, some are gardeners, and a few, a very few, are wizards prowling around on a holiday looking for something to do.