The fair Coane has found some more items of interest in regard to the above names which are pronounced as Owen. Rev. P. O. Gallachair, Hearth Money Rolls: Co. Fermanagh, pp. 208, 210 lists the following:
Hearth Money Rolls: Co. Fermanagh (1665-66)
Barony of Lurg: Letter
Cuchonnagh o Kohen (1666)
Barony of Culmaine: Cluncagh (Cullnigan)
Edmond McCone (1665)
As near as I can tell from what resources I have at hand, Lurg (Lorg) and Cul Maine may both be in the parish of Aghalurcher in County Fermanagh. A Google search for List of Baronies in Fermanagh turned up information on other counties as well. These names, with the County name first, are names that may be of further interest: Galway-Clon Macnowen (Mhac nEoghainn), Mayo-Kilmaine, Offaly-Ballycowen (Baile Mhic Chomhainn).
Whether o Kohen, Johnston or McCone are actually part of my family history or not, it shows that surnames based on (Owen) were certainly present in Fermanagh during the period of time that Barry McCain has mentioned to William Roulston as being of particular interest. That period runs from about 1585-1720 AD.
Both Barry McCain of the FTDNA Ulster Heritage Group and Joseph Donohoe of the FTDNA Breifne Clans Project accept percentages of probability of having a Most Recent Common Ancestor (MRCA) of 55% to 85% as being adequate for this prediction. Interestingly, all of my best matches are solidly in those brackets about 16 generations (or 400 years) ago, which fits the period of interest very well.
An interesting point about Parish Aghalurcher is that it also borders Tyrone and Monaghan and the Parish of Enniskillen in Fermanagh as well. In Tyrone, some of the baronies overlap the county line with Fermanagh.
Obviously, I cannot predict how any of this information will affect the research on my McCown line or those of the other four men in the Roulston Project on Maguire/McCown.