The chart indicates that Margery's first husband was still alive in 1394 and she had remarried by 1395. However, it also indicates that Thomas was the son of Hugh de Holes and Margery, and he was born by 1392.
The only way that all the information presented in Ormerod could be correct is if Margery divorced her first husband, and the only hint that that might be the case is that he quit-claimed to his mother-in-law all rights to the lands, etc. Alternately, the date of the quit-claim is incorrect and he died before 1394.