Yea the best solution for race limits would be to use a standard rounding function based around how many players are in the server. Thus races restricted to 1 per team are automatically locked.

There is an issue with blocking low level races at low player counts b/c it limits options for new players. It is better to have a system where all players are treated the same under all conditions rather than trying to limit only experienced players race selections. This is also why I am going to try to take a multi pronged approach to balance.