"Necropolis" - changes to creatures of levels 6-7.

Possibly. Try changing it in the resources so that, for example, shamans receive +3 instead of +1 to stats and morale when performing a sacrifice. The game will completely ignore this, because +1 is hardcoded into the executable, not the resources. Or the duration of Berserk, no matter how you change the spell in the resources, it will still remain 1/1/1/2 turns, because that's what's specified in the executable.

In other words, the data in the resources can easily be ignored by the executable, i.e., the game itself.

Thanks to the help of one kind person, I was able to create decent models for the Dark Knight, and improve the quality of the icons.
I am also working on weakening the Death faction.