It also includes being in the right place. Too many players depend on speed and end up not being in position when it matters. Wally is good at being where he is supposed to be.
I'm not here trying to claim that Wally is a great or even good defender. I am just pointing out that he is not a liability. This talk of his defensive weakness onoly started to come up when this trade was made. When Minesota was playing well and made the conference finals he seemed pretty adequate, and they played nothing but teams that could score that year. (Dallas, Sacramento, and LA)
Is he a stopper? LOL
Will he fit into a team defensive scheme and make sure the man he is responsible for goes where he wants him to go? Sure. Better than Hughes did. (Speaking of guys who rely on speed and then have nothing when they lose a step)