Leaving out the conflicting interpretations, and stripping it down to the known facts:
1 - 3A progenitor (name not proved) 2 - John (3A, m. Eliz. Lowe, d. Bertie Co NC 1727) 3 - Sons George, John, William (3A) 2 - Richard (3A, m. Rebecca, d. Bertie Co NC 1738) 3 - Sons Richard, Thomas, William (3A) 2 - Grandfather of Francis Pace (3A)
The question is whether the nameless 3A progenitor might have been the most recent common ancestor of the 3A and 3B lines.The DNA possibilities seem to be three:
a) The nameless 3A progenitor could have had another son, who experienced a mutation and then had a son who also experienced a mutation, thus becoming 3B and eventually fathering 3B John Pace of Surry Co NC and 3B William Pace of Robertson Co TN.In this case the mutations would have to have occurred over two successive generations.
b) The 3A grandfather of 3A Francis Pace could also have been the grandfather of 3B John Pace of Surry Co NC and 3B William Pace of Robertson Co TN.In this case the mutations would have to have occurred in a single generation.
c) The third possibility is that the nameless 3A progenitor was not the most recent common ancestor of the 3A and 3B lines.
As I said, anyone who is interested can make up their own mind as to which of these three possibilities they think is most likely.With no proof as to the paternity of 3A John and Richard, no proof as to the paternity of 3B John and William, and no proof as to the paternity of 3A Francis, it's obviously impossible to determine the identity of their most recent common ancestor.If new record evidence is found, or non-American 3B DNA results appear, that could change the picture.