Have you read the Futuh? Wallahi Somalis were peripheral people used as mercenaries in the Ethio-Semitic muslims civil wars and later on the Imam Ahmed from Hubat (In Shewa) invited some clans (Darood,Isaaq & Dir) in the war but we were only one-third of the army. The Imam's wife was also called Bati Delwambara, does that shit sound Somali to you?
He could have easily married a non Somali woman so that he could form aliances and allegiance.
The Adal empire was most definitely Somali led.