>>59660226>Or the mundane empire can have pretty strong divine magic with priests trying to convert the barbarous elves.
Having the end result be that they realize that the faith magic is very closely linked to druidic magic which is very closely linked to the arcane magic could be a cool realization in the campaign, but then the gods would need to be less forthcoming, so as to make it ambigious whether or not the faith-based magic isn't just another form of magic that they have studied to a point of science which is why it got so potent, where as the elves just simply stopped when they had everything they needed to sustain themselves and live in harmony with nature. Now that war is coming they start becoming more warlike and evocation and offensive druid spells become more of a thing. That could maybe work.
I like the idea of having different tribes of elves who the colonial power play against each other. At the extreme have the cannibal elder scrolls-style elves who are feral as hell and then have the semi-agrarian who fear them and want to find a more comfortable life or time to study the arcane, so sort of proto-high elves. I'd probly throw in some princess mononoke style spirits of the woods who have to be kept happy content or they'll unleash hell, which would act as part of the explanation for why the elves haven't advanced also.