Good post brother, but Somalis are fairly homogeneous in terms of paternal genetic lineage. The E1B1B Y-haplogroup originated in Greater Somalia and is found in the highest frequencies amongst Somalis. There may be pockets of some tribes descended from foreigners, but they are the exception, not the rule.
Interestingly, the J-haplogroup is the "Arab" paternal lineage and originates from south Arabia. Whilst there is some E1B1B present in some Yemenis, Omanis, and Saudis, there is virtually no J-haplogroup in the Horn of Africa west of Amhara territory.
Based on this, it would appear that some Arabs are descended from Somalis, and not the other way around. In any case, there are certainly some Somali clans descended from Arabs and Persians in the south.
The Tigraynans and Amhara being descended from Semitic peoples of the Middle East has long been part of their written and oral histories. This is also supported by the location of the Arab J-haplogroup in Amhara/Tigrayna territory, as well as the fact that their languages (Amhara and Tigrinya) are Semitic languages (i.e., similar to Arabic and Hebrew), whereas Somali is Hamitic (same as Oromo, Afar, ancient Egyptian).
My two cents at least. I'm always happy to learn something new lol