The pilot and the bombardier are the same person. He is either flying, or guiding and bombing. The other player that IS allowed to join is your gunner. You have all the guys you need to do the job, and do it well.
HTC said it is an either or.... Either we have "formations" or we have many players in a single buff. They went with formations. 6 guys can fly in 9 B17's (2 per formation), or 6 guys can fly in one B17. I like it the way it is.