Maybe it will upset some people, but it shouldn't, you have to go where the evidence takes you. There has been no absolute documented information that proves that the John Benfield who was in Lincoln County in the late 1700s was the son of Thomas Benfield who died in Berks County, PA in 1770. We do know, from the will of that Thomas, that he had a son named John. We know that in 1770 he granted by gift a 52 acre track of land in the Oley Hills to this son John when he became 21. We know that John and his wife Catherine sold that land in 1773. This is all documented. There are no further Berks County records after 1773 for the above John and Catherine. It is known that the John Benfield who was in Lincoln County had a wife named Catherine. Beyond that, all we have is anecdotal information handed down through the various lines of descent from John and Catherine.
I have looked at the recordof Vacant Land Entries for Rowan County 1778-1789 and am aware of the entry for John Benfield. At this point, I don't know just exactly where this might have been. This all took place at a time when boundries and property lines were being clarified. Up until about this time (1777, I think) Rowan County included all, or most, of Lincoln County. There is a reference to Buffalo Creek and it turns out there was more than one creek by that name.
It is documented that above Thomas (c1700-1770) had a brother named John (c1700-1748) who was a neighbor to the Boone family in or near Amity Township (Philadelhia, later Berks County, PA). This John had a son named Thomas who married (in Philadelphia) Ruth Mandlin in 1750. It is likely that this Thomas was in Rowan County (later Davie) in late 1750s based on witness of a Thomas Banfield to deeds whereby Squire Boone gave tracts of land to sons Squire Jr. and Daniel. This Thomas apparently returns to Berks County where his name, along with his wife Ruth's, show up on real estate tranactions up into the 1770s. No documentation has yet been uncovered about children of Thomas and Ruth.
I would be very interested in any data or information you have developed that ties the Lincoln County John Benfield to Thomas Banfield and Ruth Mandlin.