What would you change in Heroes of Might and Magic IV?

To be honest, I always thought about the 4th installment of Heroes. By releasing it without a decent map editor, they doomed themselves.

lol, what??? The fourth part has the most user-friendly map editor. You don't need to be a programmer to write a script (like in Heroes 5, 6, or Heroes 3.5). It has the largest number of diverse objects that can be added to the map compared to other installments. All of this is conveniently organized. The ability to create brushes to your liking.
Maybe you meant the random map generator, not the editor?