Agree on Young and Johnson, but down the stretch of the year Mathis was not in their league on defense. I don't know if he was trying to do too much to get more playing time, or if he'd already made a decision to leave, or what... But his defense started to become more fouling than footwork.
McConnell is probably our best returning defender, and finished the season as our third best defender behind Johnson and Young. Of the newcomers, I think Mag has the best chance to rise to the level of a plus defender. Mulcahy, Palmquist, and Reiber have the most work to do to improve. Interested to see what Hyatt, Jones, and Miller bring.