Your probably talking about Krapff tbh. The name Oromo/Orma is actually the name of ancestor. Galla is named in 19century with Aleqa Atsme ( with Be'er sm of Aba Bahrey of Gamo). So Krapff used the word "Ormanian" derived from "Orma" and "ia" which means Land of Ormas. And the Word Orma is still used but the Original and the Popular Oromo. So, don't stick to Single Reference