The real question is this: How much more can the Bills REALLY get for Henry? If the Bills are unable to get a 2nd round pick from anyone for TH, then to me this trade makes the most sense, lets get a guy who has experience in the league who can step in as a starter RIGHT away, which will benefit JP and the rest of the offense.
Plus TH will not do much for the Bills anyway, lets get a guy who can start 16 games (hopefully), and then get a RB who knows his role as a backup.