There is an open letter written by "noted genealogist" Michael Wood that discusses the parents of this Henry Sherman.
http://webcache.googleusercontent.com/search?q=cache:http://www.soy...
While I agree with most of Wood's data, his research falls short of a full examination of the evidence. For example, he says, "'Sherman' being an occupational surname, it is quite possible the Yaxley and Dedham families were not even distantly related agnately [sic]."
Yet, arms were recorded in 1660 by one of Henry Sherman's descendants. He is specifically said to be a descendant of the Yaxley family: "He [the descendant] beareth, Argent, a Lyon Rampant, Sable, between three Holly leaves, Proper, by the name of Sherman, of this family as Samuel, John, and Edmund, sons of Samuel Sherman of Dedham in Essex, originally extracted from Yaxley in Suffolk, which Edmund Sherman being of London Merchant hath marryed Jane Daughter of John Wall of Bromley, by Jane Daughter and Heire of Sayer." [Guillim, A Display of Heraldrie, 189.] The crest of the Shearmans of Dedham was "a demi-lion rampant Sable." Their motto was the same as the Yaxley family: "Virtute mortem vincere" [Conquer death by virtue].