Great points Fanatic and I found this pretty telling passage from a Boston Globe article. Most of his moves are subtle.
Bill Belichick says that he’ll only make a midseason trade if he knows the exact role that player will fill, and it’s easier for him to determine where a defender will plug in, versus someone on offense. The Patriots typically like to add a former starter that lost their job due to a coaching change and a new scheme. Sanu was a very rare offensive move necessitated by the release of Gordon.