this is nonsense; what facts you based on?All of Somalia was inhabited by Oromo. We were small nomadic group emerging from Southern Ethiopia and gradually conquered the Somali peninsula from Oromo. By the time of Adal & Abyssinian wars both Somalis and Xabashis were exhausted by war efforts. The oromo resurfaced from Northern Kenya and conquered both Somalis and Xabashis.
This lead to a butterfly effect where two large groups of Oromo split from each others embarking different paths. The Eastern Oromo retained their identity, language & culture while the western Oromo adopted Xabashi identity.