My inspiration has been perhaps to only truly successful fantasy mod, Third Age Total War.
Namely: Less factions. Quality over quantity. This leaves the possibility open for far more interesting, better and different kinds of factions, with more specialized militaries. With a ton of factions you will either end up with a bunch of carbon copy factions (like in vanilla), or you will end up with a mess of a mod like RoDG. Now I think that RoDG has done an excellent job, visually. The hours of work put behind the modelling is absolutely astonishing. However, it is extremely hard to get into because of the vast numbers of individual units they have incorporated, especially if you are not very Warhammer savvy. I would suggest reducing the number of factions to under 15, leaving the rest as "independent" or "rebel". In TATW there are like 8 or 9 factions, and some of them barely have 10 units, but the game has an immense replay value because each faction is so distinct and well designed. You don't HAVE to meet the 36 (?) faction maximum for it to be an interesting game, believe me.
I know this probably is something that clashes with your vision of what the game should be, Darrowmeres... Which is why I wont share any of my specifics with you just yet. As I said, I have a very thorough concept laid out. This includes factions, sounds, units, buildings, and I have started locating several models/textures for the units. Your map is sublime, and I really want to be a part of your project. Still want me to send you a PM?