Then I am remiss. I assumed your partners might not be switching due to inexperience. It would seem that it was actually due to apathy.
In this situation, it might have been better to ask questions that didn't indict your partners for what you obviously knew was wrong. "Are we not switching enough?" "When the ball and 8 players are Center side, should the Lead rotate over?"
If faced with it again, I would switch appropriately and bring it up at half time if it became an issue again, using that same tact.