That's an interesting idea; it would allow for creating some truly crazy things. For example, you could adapt the Thunderstorm spell into some kind of fog that doesn't deal damage but completely reduces ranged damage over a large area, and other fun mechanics. In general, it would be good to create a faction manager in some simple language, let's say C++ with QT, create different versions of the DefaultStats file, and let the player check boxes to select which factions to replace, and the application will automatically change everything in the folders. Then, all that would remain is to choose a DefaultStats version for the base factions and plan the step-by-step modification of skills. Muahaha (However, there's still a lot of work to be done with this approach :/)
Added 32 minutes later
Plus, in the current version, the ideas for mechanics have been refined, but I won't have time for thorough testing in the near future, so quick patches will be temporarily suspended (unless critical ones can be fixed more or less quickly). For now, I'll be monitoring the feedback. Especially, as comrade Dyrman already mentioned, the feedback from the original authors) (Crossed fingers, a prayer before bed). I also remember about updating the post header and providing explanatory manuals.
И пусть Эльрат осветит твой путь