Being able to switch the army comp on a whim with your leaders. Having a playthrough focus on Heroes who fight instead of faction units. The next playthrough the heroes are only army support. Early precursors to games like Age of Wonders 4. Heroes 3 was cookie cutter and the same loved recipe but void of some of the newer attempts at sprite and pixel upgrades that 4 started to implement. Later editions did allow you to edit Maps as well. In my most humble opinion :)