This is interesting. I posted my new information without going back over my old records, which I'll have to dig out in a few days. But I am fairly certain that Martha Patterson Cartwright is also buried in Tarboro, Edgecombe Co., N.C., in the Episcopal cemetery there. Actually, I don't see any contradiction.
Is it so implausible that the line works this way: -- Brothers Matthew Carwright and John Cartwright are born in Maryland. -- Both migrate to Amherst Co., Va., where they marry and have children. One of Matthew's sons in named after his brother. -- John's wife, Susanna Bowling Maddox Lee Cartwright, dies. He remarries, to Martha Patterson in 1779. -- John moves to North Carolina, along with the children from his first marriage, who show up in the records there. (It's also possible that he'd already made the move but the wedding was in Virginia because Martha was from there.) -- John dies in Edgecombe County in 1780. Martha later dies there and is buried near him. -- Back in Amherst Co., Va., the younger John marries (Rebecca Pederton according to some researchers, though I haven't seen the evidence) and has children, one of whom is my ancestor Charles. I've seen various dates for his birth, but it will have been roughly between 1784-1795. Charles later marries Betsy Paxton and they migrate with their children to Ohio.
Could that work based on your information?
Charles, incidentally, was murdered in front of several of his young children during a highway robbery near Dayton in 1832. Circumstantial evidence in the census makes me think he had at least one brother or cousin who was also a victim in the same crime. Most of Charles' children eventually migrated to the Fort Wayne, Indiana, area, where many of their descendants still reside.
When you say "evidence points," can you be a little more specific?