It all depends on the map/planeset, and what kind of mood I am in. For the last two sets maps, I flew mostly Luftwaffe, since I slightly prefer the Germans over the Russians. I got a hankering to fly Russian planes towards the end though, so I switched for a few days and flew Russian. With the current map, I will almost certainly fly Allied only, since I dont like the Japanese planes very much. On the Russia vs. Germany maps I would occasionally choose the outnumbered team if the numbers were really out of whack when I logged in, but I never switch once logged in. With this pacific map, I really cannot see myself flying for the Japanese side at all, no matter how outnumbered they get.