I agree with Ichigo and Light on this matter. Although, I do think that 10 clans would be a bit much I do think that about 6 or so sounds reasonable. To have an official clan, the admins could set rules so that a member would need to have a certain amount of posts before being able to make a clan recruitment thread (this way noobs don't spam like crazy). Another rule could be that a clan would need a certain amount of members before getting it's own private sub forum. As Ichigo mentioned, it would definitely attract a crowd.