Your discoveries are exciting. Yet I'm still a bit confused.
In your post
http://www.abtirsi.com/forum/viewtopic.php?f=8&t=9#p12 you say that genetic evidence will give you an accuracy of 100-500 generations (the time between mutations). So you might prove a common link with Aqee bin Abu Talib but you can't pove
he is the link.
I would think in the same way you could prove that there is a link between Oromo and Somali, but you wouldn't be able to narrow it down to 40-50 generations. And you wouldn't be able to prove whether it happened before or after Saamaalo.
I don't doubt that there is some link between the Oromo and Somali (after all, they speak related languages, live in the same region and even physically resemble each other!). But I would assume that this link is at least 100 generations in the past, if not more.
I still don't quite understand how the genealogical history links in with the linguistic history. You might have come across all those articles written by historical linguists that show how the Oromo and Somali languages both originated at least 3000 years ago in south-eastern Ethiopia, and how they then split and moved into different directions. Of course you can't prove that the people who spoke the language then are the ancestors of the people who speak the language now. But it would seem quite likely to me that (especially with the big groups like Somali and Oromo) that language and ethnic groups roughly correspond to each other.
So if the Oromo and Somali languages split at least 3000 years ago, how could the genealogies split only less than 1500 years ago?
Also. I would be really careful with a genealogy found among the Kenyan Ajuuraan. In Kenya, the system of sheegad was practiced
very extensively, and the Ajuuraan, for example, were vassals of the Borana for probably around 300 years. I wouldn't be surprised if the oral traditions got mixed up a bit during that time, or if quite a number of Kenyan Ajuuraan are actually Borana who married into the clan.
I've also come across the theory that the Kenyan Ajuuraan are not actually Ajuuraan but part of the Garre-Rendille group that has inhabited Kenya for a very long time. According to this hypothesis, some of the "true" Ajuuraan came to Kenya and intermarried with these people. When it was politically convenient, the whole group then adopted the ancestry of their (minority) Ajuuraan elements and thus became the Kenyan "Ajuuraan". During this process, obviously, there would be quite a bit of manipulation of genealogies.
It was fascinating for me to come across a statement made by a Kenyan Ajuuraan some 50 years ago: "We used to be Borana, but now we are Somali"!
I would still be very interested in the sources you used for the Oromo genealogies. If they are published, maybe I can get access to them here. I do have to read more about Oromo history...