Let's not turn this topic into the usual tit-for-tat Oromo vs Somalis when in reality neither of them today possess the means to uproot the other because both are under the Habesha dominance.
Truth hurts but let's face it.
Yes Somalis conquered the largest land but nothing like the fertile and riverine Oromo highlands. The only exception is small land between the two Shabelle and Jubba rivers, which themselves are born in Oromo lands. When they dam (Ethiopia has already began) or rain doesn't fall in Oromia, then you have just another dry river bed in the Somali lowlands.
So it's important to acknowledge and study your intelligence carefully.
Akisho, Jarso and Gurgura are all Oromo clans whom some switched sides in order to gain privileges because as you may know there were times it was great to be Somali. This is the same reason Rahawein clans, an ex-Oromo, joined the Somali confederates leaving their Borana behind.
The Garre are good example. If the man with the bigger stick and bigger basket is Oromo, they join that side. If the Somalis have the day, then they switch sides. Akisho, Jarso and Gurgura are the same fold except they live few miles up north.
Hawiye was never Oromo. Hawiye and Oromo have nothing in common. The bases of Somali race are the Dir (minus Akisho, Gurgura, Jarso and other claims), Isaaq, Darood and Hawiye.
Rahanweyn is today major Somali clan but historically they are Oromo who were converted to Islam before the Somalinimo door was opened for them.
Today much of Akisho, Jarso and Gurgura have abandoned the Somalis and rejoined their original family. The Garre are still funny people. Under Ethiopian flag they are Oromo but when the TPLF is not watching they are quick to attack the Borana nomads.
If Somalis restore another great state, I am confident all the shape-shifters (Akisho, Jarso, Gurgura, Garre), will pledge loyalty to Somalinimo and many will declare themselves Dir, Somali Aboo, etc.
Just recall:
https://www.youtube.com/watch?v=5tkyfljr-3w