"Thomas Mytton" is listed as the husband of "Elizabeth Burgh"--who was a daughter of "Sir John Burgh" and "Joan [Clopton]"--in an online pedigree displayed in "Guto's Wales": http://www.gutorglyn.net/gutoswales/persondb.php?ref=ns07.
"Elizabeth Burgh"--who according to other online sources should have been listed as "Eleanor Burgh"--is listed as a daughter of "Sir John Burgh" and "Joan [Clopton]" in an online pedigree displayed in "Guto's Wales": http://www.gutorglyn.net/gutoswales/persondb.php?ref=ns07.