That option is nicely implemented, giving you the idea of the exclusion area, and where the dancers will show up. But if the exclusion area were centered somewhat to the right or to the left depending on the option chosen, then people who choose 2 dancers could confine them both to the right or to the left.

Maybe that is not a "better" solution (meaning in an attempt to satisfy everyone.) I guess the question is whether the dancers should alternate sides or fill one side first, and I presume that you all discussed that at some length before deciding.