Actually, I feel that even with the principal dancers on the stage everyone is working as a team. The background dancers create the mood, the spirit, and the feelings needed for the audiance to understand the emotions being portrayed. The principal dancers are part of the team in the sense that they are, as we would say in hockey, the "frontline". They are up front and sort of "carrying" the show, but they don't make up the team. Even the people backstage that help set up and help make the sets are part of the team because they help everything come together. Honestly, if you believe that ballet isn't a team sport you haven't opened your eyes very wide. More than one dancer is needed, therefore we all work together and coincide to make one brilliant performance.