IMO every one of them offers us something we're lacking right now, at least something we're lacking in adequate volume.
Brust = Ballhandling guard with excellent shooting touch and above average athleticism. No comparable player currently on the team.
Larson = Mobile, athletic big man who can shoot it from outside or score down low. No comparable player currently on the team.
Marble = Athletic slasher type who can play guard or SF. No comparable player currently on the team.
McCabe = Versatile forward who can handle and pass the ball well, can be a playmaker from the forward position, shoots it well. Closest comparisons on the team are Fuller and Gatens, but neither is quite like McCabe.
When I say there are no "comparable" players on the team I'm not saying the incoming recruits are all better than anyone on the team, I'm just comparing skillsets.
I do believe Brust is better than any true guard we have, right now, today. But that only makes him better than Payne and Lickliter. The others have a chance to be better than some onf the current players but I don't know that any of them are right now other than Brust.