Firstly, the Italian East was composed of six Governates, each with its own capital and all reporting to Rome. Not that made any difference to the colonized/conquered people. Secondly, Ethiopia was an occupied not colonized like Somalis. It was no different than the conquest of British Somaliland by the Italians (And yes British Somaliland was conquered by Italians). I guess it is slightly since the Italians attacked a British colony, not an independent state as you would have like to sell us.
The last Sidama/Galal Governer was fascist Carlo De Simone who overran parts of British Somaliland.
Only secessionist will look to colonial history as the source of their legitimacy.