I see no reason to make fun of anyone who is for one reason or another loyal to a specific country.
And why not? Give me one reason that isn't silly as to why anyone should be die hard loyal to a chess piece in Aces High 2.
Here, I'll mock some likely responses:
1) It's where all my friends fly!
Easy, meet some new people and make more friends! If you only stick to one country all the time your missing 2/3's of the fun.
2) But we have to win the war for our country.
Way to easy. So easy I won't even get started on it.
3) My squad doesn't allow it.
This has to be the lamest excuse I've ever heard for not trying out another chess piece. Your probably in the wrong squad if this is the case. Are they so paranoid that they will be accused of spying (omg!) that the squad as a whole says you stay one country or you are out? I wonder how many people belong to these squads and also moan about ENY or being so horribly outnumbered at other times?
The list goes on, but I really doubt your going to come up with a good reason why everyone shouldn't try out the other chess pieces from time to time.