Well, that's all seventeen Magna Carta sureties and their descent to Elizabeth (Mansfield) Wilson. Frankly I was surprised that I only needed her to gain all the descents, I thought I needed some other immigrants of royal descent. And, of course, all of Elizabeth (Mansfield) Wilson's illustrious ancestry comes from her paternal grandmother Anne (Eure) Mansfield. She was the daughter of a knight and granddaughter of a knight and a lord. She lived approximately from 1530 to 1566. So she was 300 years removed from the Magna Carta and it's easy to see that she could have eighteen lines (17 barons and one king) from that time period. If you've ever researched Mayflower lines, you find that you seldom descend from just one Mayflower passenger, you descend from several. Likewise, the Magna Carta barons have children and grandchildren that intermarry, so it's easy to see that you can descend from the whole lot given enough time and intermarriage.
The question then is: Is this commonplace? Do most people of English origins descend from all the Magna Carta barons by this time? I have no idea. But you've got to take what the genealogical gods hand you. For all the brick walls which I'll never overcome, I still have a provable connection to medieval England and the movers and shakers of that time period.