Dir living in Dir Dhabe don't just "Happen to speak Oromo". It's because these oromos flooded our city during Hali Salaasie and steadily increasing migrations during consecutive Ethiopian governments.
You also forget these oromo, despite being a bunch of assimilated fools, are for some reason the most oromo nationalist group you'll see. I don't know why but Muslims in Ethiopia have seem to give up and simply submit to the Ethiopian state, leading to their newfound hatred of Somali who they see as a threat to "their" country
I spoke Oromo and Amharic for a time when I lived in Diridhaba & Addis, the administrations count anyone who speaks Oromo as Oromo, due to the weaking of the Somali region, thankfully the region is prospering now, but without a strong Somalia once the internal strife finishes the winner will set its eyes east.
The Jaarso is a special case, it looks like they absorbed some Oromos into their lineage, assimilation is pretty common with frontier clans especially in the Madawayne branch of Dir, unlike Madaluug, 80% of Dir in Diridhiba got T-L208, the Jaarso routinely fight with the Geri Koombe & the Gadabuursi are usually the mediators, since we have maternal ties with both clans.
Oromo only flock to areas of arable land, and financial opportunities like.
The city of
Dire Dawa was originally called Dir and used to be part of the
Sultanate of Ifat and
Adal Sultanate during the medieval times and was exclusively settled by
Dir clan (Gurgure, Issa and Gadabuursi). After the weakening of Adal Sultanate, the Ethiopian Christians and later on Oromos took advantage and were able to penetrate through the city and settle the surrounding areas.
Dir a settlement which according to Huntingford, may conceivably be modern day Dire Dawa. Huntingford, Historical Geography of Ethiopia, p. 122. (p)
In his book
Across Widest Africa: An Account of the Country and People of Eastern, Central and Western Africa As Seen During a Twelve Months' Journey from Djibuti to Cape Verde, Volume 2, written in 1905
, Arnold Henry Savage Landor describes the Gurgura as a Somali tribe that he encountered on his way to Harar from Djibouti in and around Dire Dawa and back towards
Abyssinia. The authors refers to the land between Dire Dawa and Harar as Gurgura. The author says he met
the Gurgura in great numbers with their spears, looking after sheep and camels. The Gurgura possessing a skin of a deep chocolate colour, and divided them into two distinct types: one with wholly hair, or twisted into curls; the other not so common, with smooth hair, which is always left long and reaches the shoulders. Some grew a slight beard upon the cheeks and chin. The author goes on to say that they all had eyes the iris of which was of a deep brown, but that portion of the eye-ball which is white was dark yellowish tone."
Landor writes about making a camp near hot springs on his way to
Abyssinia today known as Erer hot springs in the Sitti Zone of
Somali Region. There he met the Hawiya, like the Gurgura, who speak Somali, and some also understand the Galla (
Oromo) language. The author describes the Hawiya, the Ghedebursi (
Gadabuursi),
Issa, Gurgura, Haberual (Habar Awal) and Dahrot (
Darod) as speaking Somali.
Oromo political organizations sought to coerce the Oromo speaking Gurgure in the rural villages of
Dire Dawa and Oromia region, to get them to identify themselves as Oromo for their political, land grabbing and made up census propaganda though they belong to and identified as Gurgura Somalis. Oromo elders claimed that "the Gurgura people who speak the Oromo language belong to the Oromo nation and they only started to identify themselves with the Somali after the 1974 change of the Haile Selassie regime" though Somali's strongly disagree.