Who Married Mary Creber?

Its always fantastic when you find a distant cousin who has published their family history online, the thrill of seeing your own ancesters names in someone else's tree and the sense of connection. Usually there is also a sense of gratification as you get confirmation of the research you or others have done, but sometimes other peoples research can throw the cat amongst the pidgeons, raising doubts about the accuracy of your family tree. Carrying on the work of a previous generation is also both a blessing and a curse as so much has already been done, but what if someone else's research contradicts the work done by someone you know to be a meticulous researcher who looked at the original parish records?
Mary Creber was my great great great great great grandmother born in 1757 and baptised in Buckland Monochorum, Devon. She married a John Willcock in 1776 again at Buckland Monochorum. Who was this John Willcock? My mother found his baptism at Buckland Monochorum on 20th April 1752, the son of John Willcock and Mary Willcock who it seems were married in 1749 at Meavy just a few miles away. However researcher Lorna Henderson who has done extensive work from her home in New Zealand and has published her work online at http://lornahen.com has John Willcock the husband of Mary Creber as the son of Walter Willcock and Mary Morrell baptised in Meavy on 29th  April 1751. And she is not the only researcher who has Mary Crebers husband as the son of Walter and Mary. Chris and Linda Warren who's research is detailed at http://familyhistorydata.co.uk/fhd_willcock.html also have Mary Crebers husband as the son of Walter and Mary. They have identified the John Willcock who was baptised in Buckland Monochorum as the husband of Mary Reap and later Mary Austin, married in Sheepstor and Meavy. Why do they have the John born in Buckland Monochorum marrying in Sheepstor and Meavy and not as the one marrying Mary Creber in Buckland Monochorum? I wonder if any of these researchers have actually looked at the original parish records as my mother did. On the other hand both researchers seem to have done their work very thoroughly. The only solution I can see is to look once again at the original record of the marriages of John Willcock and Mary Creber in Buckland Monochorum, and the marriages of John Willcock and Mary Read in Sheepstor and Mary Austin in Meavy to see if these give any final clues as to who exactly was who.
John Willcock baptised in Meavy the son of Walter Willcock,who was the son of Walter Willcock the son of Simon Willcock. John Willcock baptised in Buckland Monochorum the son of John Willcock who's father is not known, and Mary Willcock the daughter of Walter Willcock and Thomasin Bowden. There seem to be some children and grandchildren of Simon Willcock who have not yet been identified and tied in to the whole Willcock tree, I feel sure the two Johns are closely related, and that all the Willcocks of the area are all descended from the same individual, but it would be nice to find out who exactly it was that married Mary Creber.