Andre is a solid shooter and appears to be prepared to play point guard. Welch appears a very solid shooter as well. I think both guys are more athletic than blake, but have a slower shot release. I can't see either one of them shooting over taller players that often because of the slower release but with proper ball movement and spacing they could knock down a lot of uncontested 3 pointers because they are very capable shooters.
Having watched every UK game of Tubby's Tenure, I can tell you that you don't need a fancy passing point guard to win a lot of games. Andre/Austin/maverick can bring the ball up the floor for you guys against a press. Besides there are very few pure point guards any more. Most PG's even in the NBA are 6'4 or bigger and just pick and pop guys.
When in the half court, you should run a lot of pick and roll. They just have to be good enough ball handlers on the pick and roll. Pick and roll is about timing, technique and the proper decision.
The one thing I see on your team is a bunch of slashers. Also you have 1 really good post player(Mbakwe) and 2 pretty good post players(Ralph/MO) I think Rodney/Austin are the best athletes on the team and close to the top of the whole conference. Coleman and Andre both drive to the basket and finish pretty well so that leaves Welch/Mav/Chip. Chip is pretty good at getting in the lane, not so good with decisions and finishing. Welch appears a solid shooter at the very least and probably will play some PG too. Unless Welch totally bombs he's probably got the inside track on the PG spot, just remember the pg in your offense is just a guy to get you in whatever play you're going to run. It'll be interesting to see who is better in the fast break stuff because I think you'll be pressing a lot and will get a lot of run outs off long rebounds.