Mod requests (orders).

Are you sure that this is even possible?

Are you asking me? I'm not sure, but considering how much is written in the game's text files, I assume that the values for runes and mini-artifacts are also stored somewhere there. And what, is it impossible?
I think that somewhere there must be information about which creatures can use runes/artifacts, maybe in the characteristics of the creatures themselves (although I looked in GameMechanics\Creature\Creatures\ and it's not there, but maybe it's somewhere else), or in the characteristics of the runes and mini-artifacts, or in the abilities of "Rune Priest," "Artifact Creator," or somewhere else like that. For example, in DefaultStats, it is written which artifacts a hero needs to collect to receive a group effect, or from whom and what kind of undead a necromancer can raise.