What I suggest you do is take up your research working back with source information including census, land deeds, etc. James Flatt is not listed as a son for Derck Janz Vandervliet's will and there is no evidence there is a Francis Flatt, but rather Francis LETT. The John Flatt m P Logston line matches the Andrew Flatt of PA line matches the John Flatt of Roane Co TN line matches William Flatt of NJ line, etc. And all of these are the same DNA grouping as Fletts from Orkney Island, Scotland. I doubt that there is one Flatt from whom every Flatt on the eastern US seaboard originates, but the naming conventions are highly similar for the ones in KY and TN. We know for sure that John Flatt m Mary Savage had a different entry point into the US than the Flatts found in NJ or NY.