This looks like the start of a really great mod Azurain.
I've always understood why Illwinter decided that you can't recruit enemy national units when you took their cap, but at the same time always wondered how games would play out if you could. ie. If you could recruit enemy national mages, it would likely strongly effect who you attacked first.
I haven't checked the mod itself out yet, but might well give this mod a whirl in a future game* I organise to see how it works in practise.
* A newbie game probably, as testing experimental drugs on newbs is always the way to go
