Holmes-Vandy would be absolute lunacy on defense. Both dudes are dynamite at hedging the perimeter as bigs and Vandy offers tremendous rim protection/rebounding chops to fill in some of Holmes gaps on that end. Just their energy/intensity along with what Mitchell would bring absolutely would change our culture/talent on defense from what we've been the last 15 years.
Offensively, it's a bit sketchy, but who cares? I think Vanderbilt has a chance to be a unicorn defensive big man that plays with 100% energy/hustle. He's great friends with Fox. He can't shoot, but he's not a total stiff with the ball in his hands and has shown transition ball-handling/passing talent. He's excelled as a finisher in the dunker spot, finishing the year with a 61% TS, despite absolutely 0 jumper and a bad FT%. For a team fresh off the worst defensive season in NBA history, that's a gamble worth making.