After having some battles with Stormlands, I definitely find their helmets irritating, I mean they really feel out of place, they just don't work as good as those Lannister samurai armors.
They kind of look like some wear blend of Bronze Age + Roman Helmet Knockoff and I fail to see why would Stormlands even wear them.
Another thing that I think would be a bit more immersive for this mod is if every Westeros faction could have crossbowmen, and that they simply have either a more powerful bowmen sub-tier or crossbowmen, while some factions could a have a balance between them but none of them would be really powerful. It's a bit hard for me to believe that Lannisters or the Vale have no crossbowmen.
Also Riverlands, Riverlands are utterly missed as a faction to me.
EDIT:
IMPORTANT ! Uhm Lords in the pictures of their fiefs are naked, so are village elders when I met them, the prison guards are constantly telling me there is no prisoners although there are prisoners (lords). For some reason that is only in one save/character.