Keith,
While researching the Mann ancestry I found this:
The genealogy of Richard Mann, commencing with his son Thomas, is copied from the " History of Hanover," Massachusetts, and agrees with that given in Mr. Farmer's Genealogical Register, as far as he goes with it Though what follows carries the list of descendants down to the year 1843, no mention is made of the Rev. Samuel Mann, the first minister of "Wrentham, Massachusetts, and his posterity. The writer of this sketch thinks, therefore, that Richard had another son, whose genealogy is not given till we come to "William Mann, the father of the Rev. Samuel Mann, about the year 1641.
https://archive.org/details/genealogyofmannf00mann
So it is possible Richard Man had another son, William? I also found an excerpt that Richard Man came to the United States via the Brewster Family on the Mayflower. His name misspelled as More. Found it Genealogy of the Mann Family by Rev Joel Mann.
Kristen