After all of my efforts working on the puzzle of Colonel Marbury yesterday (today, in fact, since I stayed up long past midnight), I realized that the whole argument as to whether he needs to have his own page in Wikipedia is a moot point, and nothing I need to concern myself with. For my own purpose (citing a fact in another article), all I really need to do is cite the fact from the source, and make a brief explanation (within the text of the original article) as to who Marbury was (therefore, qualifying the citation, so folks can judge whether to accept Barton's statement). And, assuming that Barton actually heard the myth from Marbury's lips, as he said (no reason to believe the doctor would make that up), then whether to believe that Marbury was knowledgeable about "Cheerake" myth and fact. He probably wasn't, that much. Just heard a few wild stories in his travel among them.
A correct citation doesn't prove or disprove the myth. Marbury may or may not have heard it from the Cherokee. It just pinpoints the probable source of a story that kept getting repeated on down the line. That's what a citation does. It shows that a man in Georgia, who likely had some contact with the Cherokee in the 1760s and 1770s (and probably a little before then), learned of a mythical people--possibly learned it straight from the Cherokee--and passed his rumor or opinion on to Dr. Barton. In order to have further proof of the so-called moon-eyed people, one would have to go to other sources, such as anthropological and archaeological studies, Cherokee myth (as documented and accepted), DNA studies, if relevant, and documented testimonies of explorers who were in North America before Barton and Marbury; if one thought such a myth could be tracked down. It's not a fact that could ever be proven, in my opinion, but by including the historical sources, we now know how the story made it into modern-day history books and pamphlets.
That's all Wikipedia wants to do--set the facts straight and document things in an objective way. Wikipedia is an encyclopedia (and one that I happen to strongly believe in). Wikipedia doesn't want vague, local-history pamphlets about mythical, romantic "moon-eyed people" who "pre-date the Cherokee." They want a citation for an 18th-century source, which mentions said "moon-eyed-people" and states an opinion, based on a rumor of the day, that said "moon-eyed-people" pre-date the Cherokee. It's all any encyclopedia wants. For those who want romantic associations and speculations about myths, there are so many other venues out there. (Get a blog.)
With the Barton and Marbury facts as a citations, the myth is documented and recorded. And, if it doesn't later get gleaned out through the collaborative vetting process, as unnecessary chaff or trivia or stuff unrelated to the subject, then it will be there for the next student or scholar or historian or myth-chaser who wants to then springboard off of it to track down some Mayan ruin or ancient civilization of cave dwellers, or whatever their discipline calls for. We only need a separate article on Marbury or moon-guys or Barton (who has already rated his own page, being a well-documented guy) if too many facts and important points start to accumulate to have any legitimate relation to the original subject, then the guy will get his own article.