But the Oromo region is the only region that matters! 60% of Ethiopia's gdp is Oromia and Addis Ababa! Oromia is the economic heart of Ethiopia. It is where the Coffee is grown, the flowers are cut, the wheat and corn that feed Tigray are produced, and where a third of the country lives. SNNP and Oromia are the future of Ethiopia, and in both regions Amharic language/culture is in decline. Oromos are even abandoning the Tewahedo in favor of Evangelical Protestantism; the number of orthodox Oromo is in free fall.
If Oromia becomes an Oromo only zone, whatever claim Amharic has to national significance will disappear. Ethiopia is a great country because of the Oromo, they are the muscle. The muscle is starting to develop a brain, it will no longer need Xabash guidance.
Sigh...we can go back and forth on this forever but the point I was trying to make was Oromo region can not pretend to be a homogenous society because it never was and will never be. Like I was saying they have to literally do ethnic cleansing to operate at the level you are describing. They may be the biggest ethnic group but they are not a majority. The 60% economy( not sure if it fact) you mentioned only exists because some of their biggest cities have a diverse community.
A better Oromo region is good for Ethiopia....a better Somali region is good for Ethiopia. A more urbanized and industrialized Oromo region is good for Ethiopia and Ethiopians. The way Somalis view Amharas is not very nuanced, so I am not surprised by your very simplistic conclusions.