I believe it is all fake
You can tell someone is Somali from a mile away but you can’t tell their clan. I believe the clans started out as small groups of people neighboring each other who were forced to come together to defend common territory. Hence why most isaaq have a common land, harti all neighbor eachother, even the ogaden and marexaan came from northern darood territory along with their harti kinsmen. All hawiye live around eachother geographically.
Once the clans were formed a back-story was added to increase internal cohesiveness. You will always fight harder for someone you believe is blood. The generations after that were then born into this clan system because the clans always need numbers and are stronger and more “laandheere”. You don’t get to choose your clan but you must have one. Paradoxically this kinda makes the clans real
In a land like Somalia, Arabia, etc clans become a strategic necessity when you are fighting over grazing land and watering holes. It is a natural evolution and those who don’t adopt a clan structure will not be around for long.
This is what Somalis today are unable to overcome. A clannish mindset that doesn’t jive with a modern state. That along with kibir, aqoondaro and caajisnimo.