We have two male Brown DNA donors who appear to be descendants of the John Brown in Culpeper Co., VA who married first to Sarah "Sally" Gibbs and second to Phoebe Brown.Those two DNA donors, however, have DNA that does not "match" one another....so something is "off" here.The second wife of John Brown named Phoebe Brown was a member of DNA "Group 10"....since two of her brothers each have a living male Brown descendant whose DNA is a match to "Group 10."The wife, however, has no effect on the results of a Y chromosome DNA test on a man.One of the two DNA donors who are supposedly descendants of this John Brown matches DNA "Group 10" at the Brown Genealogy Society DNA testing project, while the other donor supposedly out of this same John Brown matches the unrelated DNA "Group 47."So....one of these two lineages must be incorrect (and the above situation could be caused, of course, by an unknown "adoption" or an unknown "out-of-wedlock birth" in one of the two lines).It might be more likely, however, that one of the lineages is simply "flawed" (for example, maybe an apparent son was actually just a "relative by marriage" who was living in the home in question on a particular census).
In any case, it would be great to have another/third male Brown DNA donor who shows his lineage back to the above-referenced John Brown.By the way, that John Brown left his Will in Culpeper Co., VA in 1801, and the executor of that Will was a Daniel Brown.That Daniel Brown (as well as the Thomas Brown who was a witness on the Will) was almost certainly a member of DNA "Group 10," and John Brown referred to that Daniel Brown as "friend" in his Will (versus "brother" or some other relative).That MIGHT be a clue that this John Brown was truly a member of DNA "Group 47" versus the unrelated DNA "Group 10."
Note: DNA testing (so far) shows that there were at least five unrelated Brown families in the Culpeper Co., VA area in the 1700s-1800s (DNA Groups 10, 33, 47, 55 and 107).