They are two different groups. It's to benefit the colleges. Certain colleges concentrate on the academic kids because they have to. However, that doesn't mean the high academic kid shouldn't be in the other. If a player is extremely talented it doesn't make a lot of difference. One thing, normally the academic event has less over all talent than the Sunshine. This is because many very talented kids can't get into the academic, but the academic kids can get into the Sunshine.
Hope that makes sense. You can contact staff@perfectgame.org for more or better info.