At the risk of sounding like a super nerd with all my suggestions and ideas, I think combing magic resist/arcane would fix two underwhelming traits.
Perpentach usually get's magic resistance when I play him, which usually feels like a wasted trait.
It would have two effects tho, would give the leaders with the magic resist trait a much needed boost, but it might give the arcane leaders abit to much.
There really aren't any lore reasons why it wouldn't work honestly, magic resistant and arcane are interchangeable in the big picture, Sheelba grew up around magic, Auric is a reborn god.
However, +1 movement for channeling unit's that aren't disiciples sounds great, would give Tebryn a edge over gabella with higher movement witchs and conjurers instead of ritualists, but that still leaves magic resist as a underwhelming trait.
Also, expansive could use some love too, like 50% cheaper smokehouses and/or brewery