we would have to unite somaliweyn first, and prohibit hate speech towards other clans. Eventually kids and the next generations would be less tribal. Then we can include Afar iyo Oromia
You make it sound too simple. It isn't as simple as prohibiting hate speach. Clan is an identity more powerful than nationality/ethnicity for Somalis. Education works, but it's more of a long term solution; conflicts would potentially pop off within a generation or two, and if it's a democracy ppl would demand solutions that entrench the division. The only solution would be a dictator but that could lead to a rebellion.
I dont even see it as necessary to unite with these people since they have a very different language/culture/identity and they would resist enroachment on any attempt to infringe on them. Unless you want to create a caliphate and unite on Islamic grounds.