There is a book in the Family History Library in Salt Lake City about the Catawbas. The title is "Catawba Indian Genealogy" by Ian Watson, published 1995 by the Dept. of Anthropology, State University of New York at Geneseo.
I think this was written as a thesis for a degree, and the author admits it was an incomplete work. While I don't have the background to comment intelligently on his findings, I did find them plausible. His take on Catawba genealogy was that there were very few Catawba men and a lot of Catawba women. He said it seemed to be commonplace for the Catawba women to have children by Anglo men in the area. He specifically mentions the Canty families as one instance of this practice. He mentions both William Cantey and Captain John Cantey as being men well-placed to have had Indian children, as William was "the first recorded South Carolina trader among the Catawbas, from approximately 1707 to 1711" and Captain John Cantey "had command of 41 Catawbas during the Yamassee War" in 1712. He goes on to state "Undoubtedly the first Catawba Cantys were descended from intermarriages between these or other white Cantys and Catawba women." The book contained a lengthy list of Sources, which I made a photocopy of. Tommy Ingram Austin, Texas