Margery verch Gruffydd - Margery verch Gruffydd

I decided to check out this lady who ostensibly married Sir John Arderne of Aldford c1266 - June 1st 1308. I found a link on Wikitree for him and Margery verch Gruffydd. I decided to contact someone who was well versed in welsh genealogies.

It seems the connection here is bogus, therefore any purported lineages that include Margey verch Gruffydd are therefore invalidated. Here is his response:

The link made by the Wiki pedigree is bogus. Some modern person decided that "Lord Griffin of Bromfield" whose daughter, Margaret married a John Arderne, was Gruffudd Maelor II ap Madog ap Gruffudd Maelor. But that Gruffudd Maelor II was born c. 1195 and married the Audley lady, born c. 1210. They could not have had any daughter born c 1261 I have no idea who that "Lord Griffin" was, but had to be someone born a full generation later than Gruffudd Maelor II.

This is the third time I have had to call out a supposed ancestor on geni.com, and it begs the question as to how reliable are the others.