That may be the first time anything I've written has thrown someone into despair, so I do hope it wasn't THAT bad... :-)
I will admit though that I took a harder line on the accuracy of available records than many genealogists would, but from what I've read, medievalists would often be even harder than I was.There is plenty of room for opinion on what records can be trusted.In my case I chose to believe ancient abbey charters and tax records, but not county historians and peerages (books of noble ancestries) unless there was supporting evidence.That doesn't mean the county histories and peerages are completely wrong.It just means they've been shown to be less reliable than other sources.
Besides, I think the anecdotes and legends are part of our history and one part that makes it interesting.My family members like to tell their kids that their ancestors thought they were descended from the Magi Kings.I included many of the anecdotes in my narrative because I enjoy the possible connections; that doesn't mean I have to accept all the stories as fact.
This is not limited to the ancestry of the Vances, by the way; I will go out on a limb and challenge ANYONE's genealogy before the 1600/1700s to not have elements of guesswork and probable gaps even among major noble lines.The one exception may be direct lines of royalty, and even there the dynasties rarely lasted long enough for the documentation to be unimpeachable for very long.Besides, the emphasis on factual ancestries is a very modern thing... most older genealogies weren't as concerned with accuracy as we are today.That's part of the problem in believing old records.
Anyway, I hope it didn't put you off the study of ancient family history.
And, as you say, most of us - including me - are still working on genealogical brick walls in much more immediate timeframes!