Thanks for the response.
The Yibir and the Madhibaan do not have their own Language. From what I read,they merely have some extra slang which they communicate amongst themselves with. The Madhibaan are basically the blacksmith caste, groups who are looked down up all across Africa by Nilotes and Cushites. Gabooye were the hunter gatherers. Gabooye claim to have had a large kingdom called “Dhaami” in Northern Kingdom and the neighbouring areas before they were overthrown by Somali clans. I believe the history of the Harla, Yibir, the Northern Darood and Dir, even some Afar, are somewhat tied together.
My theory is that the minority groups were the first proto-Somalis to settle Northern Somalia and they could do this because of a subsistence economy consisting of Hunter gathering, fishing on the coast and tool making. The other Somalis who were at this time around the Ogaden and Northern Somali probably migrated en masse to Northern Somalia when they adopted large scale pastoralist lifestyle after they started domesticating the camel. There might have been some small remnants of Afar -Saho like people in Northern and some Semitic migrants there too, around the coast (See Apollos thread on the Somali origin). This is all Suugo science by the way.
As for the Yibir, there is a lot of confusion about their Jewish comections etc. Yibiro were basically the priestly class of Somalis, whom people visited for blessings , spiritual knowledge, astrology and treatment of ailments. I think there might have been a power struggle between them and the Islamic orthodoxy.