Some IDPA matches around here played with the team concept for a bragging rights award a few years ago, haven't heard about it lately. It was 4 person teams, each different divisions and different classes. Ie: SSP Master, ESP expert, SSR sharpshooter, and ESR marksman. Add up the total time for team score. If I were doing the the same for USPSA, I'd make it 3 person teams, Open, Limited, and Production with some kind of class point system with a max. Add up the total match points. The problem with opening it to any mix of divisions is match points are easier to come by in the less populous divisions.