Baynton family issues

A possible royal lineage may have some holes in it. Joan Baynton, ancestor of Mary Gye, is the individual in question.

Joan was the daughter of Henry Baynton of Faulstone, Bishopston, Wiltshire. Her grandparents were John Baynton and Joan Echingham, who was the daughter of William Echingham and Joan Arundel. Through the Arundel family, Joan Baynton was descended from King John [mistress Clemence].

However, there seems to be some disagreement on the Baynton ancestry. John, alledged father of Henry appears to be the pivotal person in the lineage. From various sources: A John Baynton has been inserted between  Nicholas and Robert. Two generations of Johns have been placed between Nicholas and Robert. John is shown as the son of Robert. There is also some debate over Joan, the wife William Echingham [John's father-in-law], being an Arundel.