Heroes V - Remake "File restructuring, 'junk' cleanup, and game optimization"

Nothing. The executable for Tribes of the East was taken, and patches related to the game mechanics were applied, along with minor unique edits for the Remake. In other words, the new executable is the same as the old one, but without the patch.

A small utility was used on the old executable to expand memory visibility, but in practice, it turned out that the game started behaving inadequately if not run as an administrator. GSC maps were not saved, the skill wheel did not work, etc.