Dude just drop it. Naruto clans are like sports teams, everyone has their own ones that they like and want to be a part of in a Naruto MMORPG. Also if we're talking about canon, it's not really canon to join a family through hard work, but it is through marriage and of course birth. Which, there I just gave you a good reason clans can be in any village 4 leaf uchiha married 4 different non clan ninja from the other villages and moved to said villages, thus starting an uchiha branch in iwa, kumo, suna, and kiri: the same thing happened for the other clans. Why we can't have limits on clan members? The limit if we did one, would have to rise as our player count does (if we have 10 clans and gain 10 new players the clans could get 1 new person) but wait, what if 3 hyuuga decide to stop playing NinOnline and don't delete or post that they quit? Well gee their characters still exist so I guess Hyuuga will be down 3 members. As for hard to get, you're thinking on the wrong thing to be hard to get, what should be hard to get is something like Mangekyou sharingan, EMS, or other clan moves we see rarely in the show, not the clan itself. Besides how many story driven RPGs tell you we have all these classes to pick from and then tell you oh yeah you have to play through the story a few times to unlock some of them?