Well, it would not be fair to pick on the DUP and not to have a quick glance at the UUP!
Again the obligatory health warning, surname is simply one ancestor of many, it is not who you are, it is a part of who you are, who you are is your choice, or at least it is in my book. Again, I am looking at the original forms here, there are another couple which would often be translated.
Key : * (Gaelic surname), ** (possible Gaelic surname), *** (Gaelic place-name as a surname, note these are not considered Gaelic and do not necessarily indicate any Gaelic speaking ancestors).
Billy Armstrong ** (It is unlikely in this case but Armstrong was used to translate Mac Thréinfhir)
Roy Beggs Jr * (originates in the Gaelic Beag beag, more a nickname than a surname however)
Robert Coulter ** (possibly from Ó Coltair which was anglicised Coulter)
Leslie Cree ***
Danny Kennedy * (Ceannaideach ugly headed!)
John McCallister * (Mac Alasdair)
David McClarty * (Mac Labhartaigh?)
Basil McCrea * (Mac Ráth)
Alan McFarland * (Mac Pharthaláin)
Michael McGimpsey * (Mac Diompsaigh)
David McNarry * (Mac Náraigh)
George Savage (This is an Anglo-Norman named, long gaelicised as Sabhaois)
So, 8/18 originate in the Gaelic language, almost half. One is a Norman name with a long established Gaelic version. There are three possibles.
Again, just observations.