Your right but places like barawa is different.How can they not know? Somalis are obsessed with lineage? I can’t imagine someone from a major tribe not knowing what they are and joining a small group of assimilated immigrants.
You got certain sub tribes in barawa claim they’re Arab when they’re south Asian/central Asian in reality . While others are Arabs,Bantu and Somali. They’ve formed their own community to the point some don’t know what they’re originally so they got assimilated by the other sub qabils. Random haiwye went there and married an Arab/bantu/asian or possibly a half breeders and left his children there. Hence why it’s better to study there genes (everyone sub tribes in barawa) and estimate how many comes from arab, Somali and Asian