ok lets say dunbar's number is real and you can only really know 150 people very well. so you can create clans of 150 people. lets say you can also be part of 3 clans per server. so lets say same 20,000 person server, best case scenario you pick out 150 people perfectly they are your best mates possible and you create a clan and everyone befriends each other. odds are you all play similar games cause that's how you met. this is the ideal outcome. the next clan is people you befriended haphazardly so its a random assortment of people who play the same games. you might leave this clan if other friend groups off you a place. the next clan is you got invited and accepted you didn't befriend any of these people, you might leave. so you have friends, and random people you play with out in the wilds of the server, and you have 3 clans that are trying to get the ideal people. this is the ecosystem.