I'm serious, and it's the same for all factions. When upgrading, not everyone pays attention to the characteristics of the creatures directly in the hero's army. I didn't either, and I used to choose upgrades that were more necessary for the corresponding tactics, but one day, deciding to just compare the modifications out of boredom...
There are two types of upgrades:
-simple upgrade
-alternative upgrade
Usually, one is aimed at attack skills, and the other at defensive parameters...
Are you saying that when upgrading a hero, the unit's characteristics change?
Or do you mean that secondary skills from attack, such as +1 to minimum and maximum damage, are immediately added to the characteristics of the units of that hero in the statistics window?