That model has been tried many times, since it's a natural extension of the existing tournament system that exists in roller hockey today. The problem is it's not viable, and it has failed time and time again; even with some extreme gimmicks to try and get fans in the door. In order for one market to sustain multiple teams, that market needs to draw several thousand more fans per game than it takes to sustain just one. Without a "home team" for the fans to latch onto, what inevitably happens is that they actually draw fewer fans than an amateur product like junior or college hockey. People want to feel connected to their team, it's what makes sports appealing in the first place. Having teams travel between cities means more travel costs, more planning, and more logistical overhead, but it's the best way for a sports league to work.