In fact Achamyeleh Tamiru endorsed that he is Oromo descendant by silence to the Q presented for him to identify himself if her belongs to the so called Amhara.
Leprosy hospitals in Ethiopia were established at garrison sites (colonial soldiers camp) in order to treat them. That was how it was established. Even at this time in point, you can go and interview the residents dwelling around the hospitals and ask their identity. Further, you can go and search Ethiopia's Ministry of Health Data that can tell you Leishmania and Leprosy is predominant in Gonder and Gojjam.