This is just me, but the school should add a ice hockey team. Now just hear me out.
I'm a hockey player myself, and we beat the crap outta each other on the ice to win. Thus the solution is right there.
Create a ice hockey team, and allow these people to join so they can beat the other teams and themselves up on the ice. And since its such a physically demanding sport, they will probably be too tired to beat other students up.