My understanding is a 12 marker match with the same surname or a variant is far more significant then a 12 marker match of two completely different surnames- so while it makes sense to test as many markers as possible a 12 marker match can still be of value provided the surnames also match or are a variant of each other.

I am looking for information on Milligans or Taggerts from Ballymoney or surrounding area.  In a newspaper article circa 1925 or so my Great grandfather states both his parents were born in Ballymoney N. Ireland- his father William Milligan was born abt. 1829, article states he was a Valet for a Lord Allen prior to immigrating to the US in 1847.  His mother was Alice Taggert who was born abt. 1832 and immigrated sometime after William and they married here in the US.  I have census records in the US that trace their movement here but no information on the family in Ireland at all- their parents, siblings etc.  Any suggestions would be greatly appreciated!