Hello have you tried fheroes2 ? It is an open source recreation of the game engine, with which you can improve graphics, have a better AI, unit splitting and other modification made by fans.

All you need the is the gog version (either dos or windows verions), install it and then you install fheroes 2. You point fheroes2 the place where you installed the original game, then you have an improved version.

And if you don't like it, you can use normal version as it does not impairs it. You should give it a try.

+1
Once you try fheroes2, there is no turning back. Look for ihhub/fheroes2 in Github.