I'm suspecting a problem with Valdes y Cocom's work. In looking at another piece on Frontline, I found a glaring error on Duncan Gibson's line. His ancestor Daniel Duncan is attribute to a completely wrong line. It's an error that could not have been made based on primary sources or even from any known secondary source. It's just sort of cobbled together in a very sloppy way.
Now that I find your message here, I suspect Valdes y Comcom does less than reliable work.