I think Tatsu actually stated if we get more people he might allow it, emphasis on might. I think they want us to improvise on work with what we get even though it might now be what we want it's nice for a challenge.
At the same time if you already have developed characters with custom clans and all then it gets more tough, but as I stated it is a challenge and it can be fun.
I'm all for this, but I'm also okay if we don't get custom clans. The only reason why I'm all for Custom Clans is because since day 1 there has yet to be a day when I don't bring it up.
But with Custom Clans come with more difficulties. I think we're lucky to have custom jutsus and weapons though because how cool is that!