Percy Beauchamp's Strange Accomplice

So, Percy Beauchamp is following Fergus around trying to convince him he's the legitimate heir to a vast tract of America. When they finally talk at length in Charles Town, Percy is with a strange man who Fergus thinks is an evil man and the one behind this plot. Anybody have any notion who this man is and what he's up to? Just btw, the man states confidently that the American rebels will win the war. I can only think of one way (in the Outlander universe) that he could know such a thing.