The Maigh Seola information has finally put the pieces together for me, and all this time I was concentrating too far east thinking these surname hits were not related. I've done a lot of reading wherever I could and this seems to indicate that FT130287 was a "holdover" and did not make the Breifne migration.
The Ui Briuin of Maigh Seola (Clare b., Galway) conquered the Conmacne Cuile Toladh (Kilmaine b., Mayo) in 766 at the battle of Shrule. The Ui Briuin were their overlords until 1118. The growing power of the Ui Conchobhar on their eastern boundary was as close as Tuam. The Ui Conchobhar invaded Conmaicne Cuile and pushed out the leading sept of Ui Briuin (the Ui Flabheartaigh, aka Muintir Murchada). I think it might be evident that FT130287 was a lesser-family, maybe only temporarily "chiefly" centuries earlier, being planted with the Conmaicne, but had long been integrated with them.
After the Norman invasion, the Burkes took the whole area and split into Mac William & Clanricard approx 1330 after they had completely gaelicized. The Mac William Burkes, prior to the late 15th c., employed seven septs of Clann Domhnaill's galloglass. One of which, the sept of Aedh Buidhe Mac Domhnaill was given extensive lands in Kilmaine, and had become a lordship unto themselves, and built seven tower houses. Clann Domhnaill, until the collapse of the lordship of the isles, contained contingents of Mac Giolla Eain. The O'Fearchair would likely have been tenants of the MacDonnells of Aghalahard where there were certainly Mac Giolla Eains present.
Several months ago I found a match to Gorry, by the name of Gurry. "McGurry" was present in low numbers around Tuam & Galway, seemingly a variant of a different surname. Near Shrule on the border of Conmaicne Cuile was "Curry" which I take to be Mac Mhuireadhaigh, which probably also had a Mag-prefix. Muireadhaigh was a popular Ui Briuin name, of which there were several kings of Connacht in the time frame of FT130287's development, who were "mac _______ mac Muireadhaigh".
Although the next matches are not concrete because they've yet to respond to my emails, I've got several Henleys (Hennelly; Ui h-Iongaile, or as Woulfe thinks it: Ui Fhionngoula) as well as several Garveys (Mac Garbheith), both of these families were numerous in the same parish as the Ui Fearchair.
On a side note: I think the new Muintir Echach member of Joyce, who came from West Galway is another indicator of A5902+ holdovers of another clade (FGC34296)

I now believe the MacLeans probably also served Clanricarde and O'Kelly. The townland of Toormacleane lies on the Sligh Mor, along which there are breadcrumbs of McClean records from Ballinasloe to my MDKA in Clara, Co. Offaly