In RCU's case, the computer deals with boats on the same frequency and does not put them in the same heat. This was one of the orginal parameters we set up.
However, we have come across the situation where people do choose the same frequency for exactly the reason stated. To avoid raicing each other and to help each other out. We never really cared much about but then the past two years some father/son teams have done that. They do it so they can help each other out, but in actuality it gave them an unfair advantage over others as they never had to race each other.
We decided that to be fair, all boats in the top 20 in season points needed to have a dedicated frequency, different from everyone else in the top 20. This meant if you weren't in the top 20 and therefore more "recreational" racers you could still team up. However, if you were a more serious racer you had an equal chance to race any of the other top racers and no one didn't have to race against a specific other racer.
We had some initial grumbling over how we were "picking" on several people, as they needed to help each other. It was curious though, how they alwaya were able to find someone else to help when they both made the final. Finally after some good and heated discussion they understood the point and agreed to get on different frequencies. I think the key thing we learned as a club was, people don't care what you decide, as long as you include them in the discussion and try to make things fair for everyone.