Not really. Hayes is good defensively. He's got nothing to offer offensively though.
Hayes has been a + player the past two games. Valanciunas is -22 right now.
Meh...much like hockey plus-minus is not a great indicator of individual play. JV has struggled for sure, but I don't think you can be a good defender as a post if you offer zero rim protection. He's an ok rebounder, if the ball comes inside on a drive or if he's isolated in the post as a defender, he's SOL. If he was 250 lbs and a little more mobile, like his Houston days, he'd be an average defender, at 280 or whatever he is now, he's poor.