1. The idea that Edward of Leyden could have been the son of Thomas Southworth of Wells, Shropshire arose from an apparent error in Justin Winsor's book, "History of Duxbury, Mass." wherein he stated that Constant and Thomas Southworth were the sons of Constant and Alice Southworth (nee Carpenter) and the grandsons of Thomas and Jane (nee Mynne). This Thomas, however, did not mention any children in his will, nor did his mother in her will. Documents show that Edward Southworth was married to Alice Carpenter, not Constant. See "A Genealogy of the Southworth descendants of Constant Southworth" by Samuel G. Webber.
2. Edward of Fenton was shown to be 36 years old in 1608 which would have made him 41 at the time of his marriage to Alice Carpenter. This would have disqualified him from being described as a young man ("jongman") in the Leyden marriage record. See "The Ancestry of Ensign Constant and Captain Thomas Southworth of Plymouth and Duxbury, Mass." by Frederick L. Weiss.
3. Edward, son of Robert of Clarborough was, according to the visitation of Nottinghamshire, married to Ann Elsam around 1607 which disqualifies him from further consideration. See Webber's book. Robert of Clarborough had a brother who also had a son named Edward (see next item).
4. Edward, son of Richard of Clarborough was born in 1585 had a brother named Thomas, born two years earlier. It is possible that this Edward could have been Edward of Leyden. Webber and Weiss conclude that there is little to connect the two, but Robert French in his article "Who was Edward Southworth of Leyden" (Mayflower Quarterly, Feb. 1992) demonstrates that Thomas Southworth (Richard of Clarborough's son and Edward's brother) left a bequest to a man named Nicholas Watkins, who was also left a bequest by a woman named Anne Peck went she to join the Pilgrims in Holland. French concludes his article by naming Pilgrims John Robinson, Richard Bernard, Richard Clyfton, John Smith, Hugo Bromhead, William Brewster et al as having ties to the Southworth family of Nottinghamshire.
5. Edward, son of Richard of London, would have been 52 years of age at the time of his supposed marriage to Alice Carpenter and again would not have been described as a young man on the marriage certificate. See Webber and Weiss.
6. Edward was the seventh son of Thomas of Samlesbury and Webber concludes, that as such, he would not have had a very great inheritance and would have had some reason to leave home. Webber clearly believes that his Edward was Edward of Leyden and notes that Myles Standish came from Duxbury, Lancashire and that it is not improbable that they were friends and so together joined the Pilgrim band. The Standish family worshiped at St. Lawrence church which is less than ten miles from Samlesbury Hall.
John Southworth draws the following conclusions: "There is no denying a Nottinghamshire Southworth/Pilgrim connection" which can be established by considering the marriage of Samuel Fuller of Nottinghamshire to Agnes Carpenter (Alice's sister) in 1613. There is also a clear connection of the Samlesbury family and London (where Edward of Leyden lived prior to his death in 1620).
Edward of Leyden appears to have been both a merchant and business agent for the Pilgrims and so was presumably literate, which was largely the prerogative of the wealthy. There is no record of Edward of Samlesbury's education, but his brothers Thomas and John attended Oxford.
Edward of Leyden was married to Alice Carpenter of Wrington, Somersetshire. A branch of the Samlesbury Southworth's lived in that same county about twenty miles south west of Wrington.
G.C.S. Southworth, in 1897, mentions that a kinsman, Mr. H.W. Southworth, visiting Europe sometime before then , met a Mr. Baron of Blackburn (the township of Samlesbury was in Blackburn parish). Mr. Baron told him that Edward Southworth of Leyden was the son of Thomas Southworth, eldest son of Sir John Southworth of Samlesbury Hall.
John Southworth concludes by saying that "if the Samlesbury/Leyden connection is an old established belief/tradition, predating any later evolved alternative views, then it is likely to carry more weight. There does not appear to be any old belief/tradition concerning any Nottinghamshire connection."