Isabella is a bust - what great quality is that? If he couldn't learn something from Larry Fitzgerald, who on the Patriots is going to take him under their wing?
Isabella's 6.95 3-Cone is unimpressive for such a small guy. Tre Nixon has a 6.81 3-Cone. Isabella's strength is speed, and as noted by
@WinstonSmith, Hall is faster.
I don't see Isabella in the slot (not shifty and too slight of frame), and not sure what he adds that Zuber, Nixon and Hall don't already provide. Zuber and Nixon are fast, more shifty than Isabella, still learning and growing, and might develop into solid players.