Your point about the importance of full brothers is very interesting. When I first went through those Wills I was not aware of two wives, so did not distinguish between full brothers and half-brothers.
Your point also about the lack of modern resources for those earlier antiquarians has also made me think hard. It now looks as though for all the data after 1564, those authors (Colby, Vivian and Jennings Wise) all relied on the same information supplied from a single archive in the possession of the grandchildren of Ayshford Wise (my GGGF’s banking partner and MP for Totnes in 1812-1818).
I am therefore willing to reconsider the tidy solution to this whole question. If Emmot was a misreading of the name Willmett, then John Wise the Elder could have been the son of John and Alice (nee Harris) who appears in all those original trees. That would then make William (married to another Wilmote) and Samuel (married to Frisweda) to be the sons of Elizabeth Smythe, and half brothers of Christopher, Eustace, John and Nicholas. That is very clean, but hard to substantiate. Maybe you knew all this when you first started this thread, and it has taken me a while to absorb it all.
btw, I downloaded a copy of Vivian's "Visitations" book some years ago, and I think it is still downloadable for free from
https://books.google.com/books/about...d=GmqlIibS95IC.