Not really, sure most members have a common lineage but I'm pretty sure the clans intermingled with normal shinobi, without genetic diversity they would've died off so incest wouldn't be practical. Sakura is Uchiha imo because she's married to one and has kids with one.No I am soloing. Don't you see the difference?
A Clan is basically another way of saying race. Obviously Kishi did not wanna seem racist hence why he did not mention it as race.