I like to play british and NATO in CMSF2.
I will appreciate the opportunity to play another nationality like Polish or French forces. Uncons (separatists) with radio or other communication equipement too.
And, in my opinion, Turkey would make a really interesting opponent, as in term of material and doctrine (mix of NATO and new material made in the country) and also because this army is characterized by an upmarket movement since last years. More, it could rather be integrated in the NATO camp or in a more cloudy role.
With uncons and mod working, Turkey would open a lot of perspectives (fight against Kurds, in Lybia, against Syrian or even Russian forces...).