Of course, a number of things should have been reworked: the bonuses for Mysticism, Magic, and Learning skills should have been improved to reasonable values, the effect of Camouflage should have been fixed at the Advanced and Expert levels, ideally, Resurrection and Raise Dead should be made equal, and the effect of Resurrection without Earth Magic should be made permanent, but this should have been done 10 years ago, and today, even if such a mod is released, few people will play it, because everyone except beginners has become accustomed to a certain state of affairs over many years and simply don't take useless skills, and Camouflage, if it's not a basic skill, is not used (does anyone even remember it?).
But these, to put it mildly, are bad ideas: to make an overpowered thing even more overpowered. No one will play "Heroes" like that.
I think that now, no matter what, few people will play it. Although some "Heroes" communities (I mean groups of people) could quite possibly play using their own patches with minor changes, since everyone has a completely different opinion on what needs to be strengthened and what needs to be weakened (I have already become convinced of this).