Again, thanks much for taking so much time to break this down. I agree at this point, given what documents have so far been found, that theory "B" is more plausible. I'm probably being redundant here, and I'm afraid I offer no solutions, but just wondered about a couple of things.
Have any other documents been found for any name (Darwin, Dorwin, Durwin, etc.) between Thomas "Dorwin" arriving in America in 1647 and the time of the Hardy deed in 1746----almost a 100 yr. period? It seems that, even if this Thomas was an indentured servant and couldn't marry or own land until he paid his debt (not implying that he was, just covering bases) that at some point his name might show up on a parish church record, tax roll, etc. Perhaps it did and the records have been lost.How thoroughly has the family of the Wilkerson/Wilkinson's been investigated around the 1730's period? Does the name show on any records in Louisa or surrounding counties at all? It seems that a lot of blanks might be able to be filled in if more could be found out about the aligned families. These young people didn't just go to a club and meet and marry! The families knew each other and intermarried for generations, many from the early 1600's to the later 1800's--or so I've found in some of my other family lines.
Anyway, no solutions, just thoughts. Do appreciate all you have taken time to write about your theories, and please keep us all informed if anything new comes to light.