I think at D2 and D3 that is often the case. But at the high level of D1, at least you will get stud SFs to play SF. However, it still isn't uncommon to have a SG, PF, or C play SF. For example last season on my WVU team I had a PF playing SF, and this season I have a SG playing SF, but next season my starting and backup SFs will both be SFs.