Every single Somali Bantu has slave trade associated ancestry, it doesn't matter if a tiny portion of their ancestry got their voluntarily. They all have mixed with slave trade Bantus, so all Somali Bantus DO descend from foreign slaves.
As for Benadiris. They are a bunch of Gujarati-South-Semitic-Swahili mutts who do not have any rightful claims to Somalia over ''Samaales''.
I remain offended.
What you have written here is exactly what I am talking about. The "one drop" rule was also part of slavery in the American South, until Northern sensibilities and the Civil War put an end to it.
Mutts are often the very best dogs. It's the inbred pure ones that get the little deformities and the touchy, insecure personalities and short lives.
The Benadiris certainly have a claim to Benadiri culture. At least check out the archaeology of Mog and the Benadir.
This is the 1977 clan map of Somalia, before Siad Barre started leaning on the Minorities, confiscating land, etc.:
The Gosha and Mushunguli are the single pink area northeast of Kismayu. The Gabawiin are up the Jubba, the Shabelli up the Shabelli, the Makaane and Shidle in the Middle and Lower Shabelli., and the Eile, Eyle and other Af Helledi speakers are in the inter-river area. This should make it clear that the enslaved population was significantly smaller than the free population. Only the Gosha and Mushunguli were enslaved.