This is a snapshot of the Myers DNA Project, showing the Myers R1b group, lineage X. Terminal ancestors in this group are William Myers Sr, who passes in TN in 1823, Charles Myers, who passes in MO in 1857, and John Myers, 1742-1826, born in NC, and passes in MS.
Now, a lot of the Myers in Greene Co TN are actually haplogroup G, as opposed to the more conventional R1b (not that R1b-P312+-Z39300+ is a typical German)
Now, let’s get to John Myers/Ann Bruce. It turns out the known documented descendants of this pair are R1a, not R1b. And R1a doesn’t transmogrify into R1b overnight. They are the R1a-lineage II below. I know from personal conversations with Neil Myers that all those R-YP639 assignments are backed by a BIGY test.
One of the take homes from this analysis is that the common birth date assigned to John Myers NC-MS may just be a fabrication, chosen to be identical to a John Myers child born to John Myers+Ann Bruce. We do know he was married, and the date is often given as 1774, and that he was old enough to be a Rev. War veteran. But the exact date of his birth may be hard to find.