If I recall, every single tag in Ireland has either full units or at least Tier 1s (I think it's a situation where pre-RB tags got full models and tags added in RB got only Tier 1s, though the regional unique is applied properly so they never look generic). Cornwall, Wales, Northumbria, and Man also have full models. It's actually one of the most well covered regions in the game.
Okay, thanks, though I don't think Gaeldom has, not sure about The Isles, and don't think all the releasables in France or Iberia have unique models. Having said that, I do think it's the Scandinavian/Baltic region that would benefit the most
Considering people seem to want the Baltics, SA, and Africa to be the next focuses for regional content design, I have a feeling the Baltic has it in its destiny unless they cancel EU4 after Leviathan (which considering they're asking for fan suggestions here I doubt they'll do). Scandinavia is also one of those formables that has no unique units assigned to it that we keep bringing up.
I agree, Scandinavia and the Baltic area would be the top of my list for attention, then Africa