The northerners should be most like the Vaegirs, I believe, but without all the steppe elements they have been given (like great archery, and the North should not have any named knights). The Nords are based on the Vikings, just like the Ironborn in ASoIaF. The northern armor should not be great, but they should have pretty good strength stats. I always imagined the northern troop tree going like this:
Northern recruit - Northern soldier - Northern man-at-arms - Northern veteran - Northern Warrior - Northern Berserker (a-la Great Jon)
/ Northern Cavalry - Northern mounted warrior
Northern skirmisher - Northern archer - Northern Marksman (the north does not have very advanced archery)
In general, the Northerners specialize in melee infantry, so all cavalry should have weaker stats then their "equals" in the infantry section.
The Dornishmen should be Sarrinid-like, most troops armed with long spears, and fast swords like scimitars (in order to prevent the fistfighting-spearmen the Rhodoks are suffering from in Native). Out of cavalry, they should have light and fast desert cavalry armed with long polearms capable of couched lancing, and horse archers with curved bows - meaning that your troop tree fits them perfectly, mr. Freshh.
The Westerlanders should be Swadian-like, with medium infantry, crossbowmen and heavy cavalry.
The Reach troops should be very well armored, the top tier archers recieving the BEST light, the heavies recieving the BEST heavy equipment, but their stats should not be so high. Otherwise, their strengths and weaknesses are very similar to those of the Westerlands.
The Stormlanders should be focused on defensive, with no great cavalry but good crossbowmen and archers, along with defensive melee infantry (like powerful, heavily armored macemen). They should have the highest proficiencies due to their strong martial traditions.
The Vale troops should be fitted for fighting in hilly regions, as they have spent most of their time fighting mountain clans surrounding the Vale and defending the bloody gate.
The Riverlands should have medium melee infantry (the one that I imagined closest to the Swadian melee infantry) , excellent archers (like Blackfish
) and weak cavalry.
We are going to need one more faction than is present in Native, but I don't think it is a good Idea to do things Brytenwalda-style. Warband implemented plenty of features that allow lords to choose switch their alleigances ASOIAF-style. We are going to have 7 factions for now, and might add an eight one later (the Ironborn) but there is a possibility that they would simply be sea raiders.
Sadly, I don't know how to make the recruits spawn at the villages. Hell, I couldn't even make the Lannisters to stop using Stark troops