After we learn how much of us are going to play, we have to see on what side will bigger part play. This way, we could rule out which side will our guild take. Predictably, you will have to have at least one character this side so we can play together. If this is not going to be your primary character (out of different affiliation, for example) than it will only be required to have either Trooper (Republic) or Bounty Hunter (Empire), no dividing in here.