Paul; What you heard about Francis Segraves was just speculation, unsupported by any documentation. Serious researchers continue to look for undiscovered sources that will identify Francis' origins.
I am very familiar with the Arkansas branch of the family since Gilbert was my GGGGGG grandfather through his eldest son, William. My greatest challenge in recent years has been to connect Gilbert directly to Francis and Lucretia. The records of pre-Revolutionary North Carolina are sparse at best. We believe that Gilbert married Sarah Wilson in Ashe Co., NC in about 1815 or so, but the Ashe County courthouse burned several times and all such records are lost. A treasure would be an old family bible with such dates in them.
In all, it continues to be an intellectual challenge piecing together this family. We should all be cautious about making undocumented statements about the family since many people reading these postings are not careful about checking the facts before using the information. If you do have source material about Francis and his descendants, please let us all know of it.
Best of luck in your research,