For dyccan/Alneyan:
Wouldn't it be possible to just make the special spells of Ermor themes national spells of Ermor? This would give them to base Ermor. You could even change the unholy spells as they are unique to Ermor (I think) and your mod won't probably have any unholy priests... Besides, if you changed Ermorian Cultists and Ghouls vampires could just turn up and attack your enemies!
For Thufir:
What about this: the army with faster strategic move moves first. If the army moves in owned province, they get a bonus of +1 to their strategic move when the moving order is considered. With this chance, armies consisting of light cavalry and other troops with Strat. Move of 3 would always catch armies consisting of heavy infantry.
It woldn't help against Caelum though, and would make it very easy for them to repel raids. But then, Caelum is meant to be a good raider...