@harpo that is an issue with the 'autoresolve' button exclusively and has little to do with how overpowered-or not the Heroes are, which is the crux of this posters concern.
I have however mentioned previously that the rediculously slow tech advances are part of the issue. Heroes can clear the map by about turn 200. Now maybe this is a reasonable period of time that the game is supposed to last, but if so the player/ai should be able to research equivalent army techs to match by this point, and create more than easily destroyed fodder.
However, maybe turn 200 is too fast and turn 400 or 500 should be necessary to kill the prevalant monsters. However technology is =still= an issue, as it is impossible to properly outfit your army by that turn to compete. Not to mention without the heroes clearing the area for new cities technology will advance even slower.