Unless it would cause bugs, I can't think of any real reason not to let players change their country's map color, unit models (provided they've bought the DLC for the model they want to use), and even country name (but not tag, obviously). It would add a lot of fun to players who both take the game and history very seriously AND those who don't take it seriously at all. Plus, some of that functionality now already exists in the form of Client states.
Players who take the game very seriously could then model historical outcomes of their own nation however they'd like, and would be able to, for example, use the Genoa unit models when forming Italy from Genoa without downloading mods or altering code or requiring the devs to do anything about it. They could change their nation's name to that of a country that didn't exist during the game's timeline but could conceivably have done so without requiring the devs to waste time and code on things that were unlikely to happen (Yugoslavia? Czechoslovakia?).
Alternate history nuts could switch from Byzantium to The Roman Empire once they retake Rome or unite Ireland, take over Great Britain and declare themselves Celtia. Start as Navarre and re-build the tribes of the Vascones!
And people who take it not-seriously-at-all could make the Empire of Kickassakstan or the State of Denial, using all Aztec unit models, or play as a country that never even came close to existing during the timeframe of the game.
It would add more fun, it should be done!
Players who take the game very seriously could then model historical outcomes of their own nation however they'd like, and would be able to, for example, use the Genoa unit models when forming Italy from Genoa without downloading mods or altering code or requiring the devs to do anything about it. They could change their nation's name to that of a country that didn't exist during the game's timeline but could conceivably have done so without requiring the devs to waste time and code on things that were unlikely to happen (Yugoslavia? Czechoslovakia?).
Alternate history nuts could switch from Byzantium to The Roman Empire once they retake Rome or unite Ireland, take over Great Britain and declare themselves Celtia. Start as Navarre and re-build the tribes of the Vascones!
And people who take it not-seriously-at-all could make the Empire of Kickassakstan or the State of Denial, using all Aztec unit models, or play as a country that never even came close to existing during the timeframe of the game.
It would add more fun, it should be done!