What you have to do is go through the country file and change the codes for army (circled above).
For example, Bavaria has its own sprites (at least for two levels), so you should change 'GER' into 'BAY' Meanwhile, I've split up the minor states into German (GER), Italian (ITA), Western (HEL) and Eastern (HUN). Bearn is in Western Europe, so you should change 'MIN' into 'HEL'.
I'm not familiar with Plvs Vltra, so I didn't make a country file for that mod. I'll probably do so at some time, but I'm quite busy at the moment with other things.
Thanks
What are all your codes and what areas/nations do they represent?
example ...Does BAY mean only Bavaria or southern German states