Give the choice to the players...
You can choose A: to join the arena and chesspeice of your choice and just have to wait for clearance from the tower before you can sortie.
OR
You can choose B: join a different chesspeice for a little while and get to sortie immediately, might even make some new friends that way.
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See? You're not loosing freedom of choice, you're just getting more clearly defined choices to make using your freedom to choose.
FWIW...I'm startting to side with those who advocate a limit on sorties. I think GVs would have to be left out of such limitations though. For example, each country can only have X# (+/- Y%) of aircraft in the air at a time. so when a countryman dies the next guy in the launch queue get clearance to roll. Whether this is done as a base level, or sector leve,l a front level, or total arena population level I'm not convinced. I think all would help so do whichever required the least coading. But if a player does not want to wait in the launch queue he can always roll a GV.