Why is it automatically assumed that he is playing the two? I understand that in this type of offense the 2 and 3 are basically interchangeable, but Briscoe is about 2 inches shorter than Murray; wouldn't it make more sense for him to play the 2 in a more traditional offense and Murray the 3 because of size?
On offense, it doesn't matter. They will rotate through the MOTION offense. Sometimes Ulis will be at the point, with Briscoe and Murray on the wings. Sometimes Murray will be at the point, with Ulis and Briscoe on the wings. Sometimes Briscoe will be at the point, and Murray and Ulis will be on the wings.
Defensively, Ulis will likely always guard the other team's PG. He is most effective applying on ball pressure and the PG is usually the smallest guy on the floor for the other team as well.
Briscoe is a very good defender and is 6'3.5 and 218 lbs. with a 6'8 wingspan. He can guard the 1-3 spots. I think he will guard the best perimeter scorer on the other team regardless of whether they are the PG, SG, or SF (just my opinion).
Murray guards the other wing, of course. At 6'5, 205 lbs. with a 6'7 wingspan he should be able to guard anyone on the perimeter.
Mulder or Matthews end up being the first backcourt reserve off the bench and fill in at the 2 or 3 spots.
When we face a big, strong, physical SF, then Poythress slides over to the 3 to guard them. With Dekker and Lyles gone to the NBA there aren't many 6'9, 230 SFs left in college, so I doubt that becomes an issue. Still, it's nice to have a guy like Poy in there with that kind of versatility.
Labissiere can guard the 4 or 5 spot.
Lee can guard the 4 or 5 spot.
Wynyard guards the 5, if we have foul trouble.
In short:
Ulis- guards the 1 (or smallest guard).
Briscoe- can guard the 1-3.
Murray- can guard the 1-3.
Poythress- guards the 4 spot, slides to the 3 if necessary, might occasionally have to guard a 5.
Labissiere- guards the 4 or 5 spot, mostly the 5.
Lee- off the bench, guards the 4 or 5.
Mulder (or Matthews)- off the bench, guards the 2 or 3.
Wynyard- off the bench, guards the 5 when we have foul trouble.
That's how I see it.