I would like to introduce hero specializations, like in Heroes of Might and Magic III or in Demigods. Otherwise, all heroes of the same class are practically identical – in my opinion, this isn’t a very progressive feature. Although, the leveling and skills in Heroes of Might and Magic IV are much more interesting than in the previous games.
In Heroes of Might and Magic III, this is a subtle feature. The most experienced players (not me) always look for their own unique hero. But I never fully understood it.