I have been searching for this same answer myself. My husband is a Perry from Indian Bayou. He's off the Richmond Perry (b 1822) line. I also believe that John is not Thomas William's father. At the Houston library I found this document that states:
William (Manchac) (John & Pennelphy Perry) m. 23 Nov. 1813 (St. Martin) Nancy Folk (Faulk).
Right under this is:
William (England) (William & Isabel ---) m. 10 Feb 1793 (St Martin) Marguerite Rochael (Roger).
I'll look into the 2 names you found and let you know if I find anything. I have racked my brain on this one for quite a while.