Participant number 170, at this web page, gives his lineage as leading to John Lewis of Westerly. However his DNA results do not tie to that lineage. If his paper trail is accurate, then it may mean there was a non-paternity event in his families past. That is, someone cheated.http://lewissurnamednaproject.com/test_results.htm
Group 13 all tie together DNA-wise, but clearly some participants do not know in what way they are related to John of Westerly.
George of Barnstable is in Group 8, so unrelated within several hundred years at least.
You're right, I couldn't find Edmund Lewis's name in anyone's lineage, so I guess none of his known descendants has participated. As far as John Lewis of Westerly's ancestry, the only evidence is family tales, that is, all the various families I have spoken with, widely separated and unknown to each other, all replied that they believed that they were Welsh. Not proof of anything, but I put some stock in circumstantial evidence. That's the first place I would look for more evidence. Until it is shown that he was related to another colonist family named Lewis, I prefer not to speculate.