Mod requests (orders).

That's a logical question, but why would you even need to change anything if the final Knight will be a copy of the original creature, and vice versa, and you initially have the original creatures that have simply exchanged their artwork? From this, the question arises: who would do it, and why, if it doesn't make much sense?

Added after 12 minutes
A mod / map / or something else is essentially a renamed zip archive in the form of a .pak / .h5u / etc. file. You can open any mod with WinRAR / 7z / or another archiver, go to GameMechanics / Creature / Creatures / (Necropolis / Neutrals) / name.xdb..., and simply change the parameters.