The oromo did not gain any ground until displacing Somalis became a state backed project 100 years ago. Ethiopia has been supported by western governments since they arrived.You have to admire the Oromo ethnicity, 500 years ago the clans that were part of Ahmed Gurey’s conquest of Ethiopia were mentioned as Somali, Richard Burton mentioned these clans as Somali 150 years ago. Then we converted the Oromos to Islam and instead of them becoming Somali and adopting our language as we taught them Islam, they instead assimilated and integrated Somalis into their clan and continuing their expansion by assimilating all the langaabs on the border. If we were more egalitarian, most of Eastern Oromo would be Somali. Siad Barre had the wisdom to label them Somali Abo and they wanted to join Somaliweyn.