Knicks need front court depth, not just to backup Mitch, but to replace Mitch when he gets injured. Stewart is far from a beacon of health himself(only 46 games last season), but has generally been more durable. He offers good defense, very good rebounding, and ability to stretch the floor not usually seen in Knicks big men(38% from 3 last year). Though on the shorter side at 6'8, he has an almost 7'5 wingspan and was among the leagues best in contesting shots in the paint(players shot like 12% worse when he contested shots at the rim). I think McBride is a better player and def on a better contract, but McBride wouldn't get much run time on this roster especially if Kolek or Payne is taking backup 2 minutes.

Pistons get a promising young guard in McBride who they could probably swap for a first to a team in need if they wanted or let him duke it out with guys like Ivey and Sasser. Sims and Precious both don't have high ceilings but maybe they gain some value on shitty pistons team.

throw in a pick either way if you feel like it.

Oh extra note. This clears up a roster spot for the Knicks to sign an extra player. This could be used on the buyout market or something.