About changes and/or combining Hero Specializations.

Changing specializations is only possible by modifying the .exe file.
Or by using scripts.

As I understand it, scripts will only work within a single map, not for the game as a whole, right?

But if we're talking about the script-based version, it would be good to have more details. This could be useful for one of my projects, to create more interesting Hero-Bosses, without being limited to campaign-specific overpowered abilities.