Sweden is in the Battle for the Baltic 2.0 mod, currently for 6.1(where Sweden replaces Ireland). Good mod, I recommend it, it does a full overhaul of the Scandanavian units.
And yeah, Scandanavia is a little over represented, but I <3 me some Viking stuff, so its good by me. And IMO, the "three factions in an area" is a good thing, more fighty in the early part of the game. This isnt Age of Empires where you have some really lame units in the first age, this is Total War!
Iberia has Protugal, Leon-Castille, and the Moors and possibly Aragon. France has England and Aragon(I normally dont see the HRE going after France), Italy is well known for it's factions
