Another interesting statement. I agree with the true PG statement, but let's look at why a coach would want someone else at Point, instead of Brown and Reese and any of the other guards available right now (Ryan should fix this issue). Lawson and Johnson are SGs period. Brown has a scorers mentality and gets out of control if he's in the PG position too long. Plus, with his scoring ability, you should want him off the ball in position to score.
Reese is a turnover machine- at least he was last year (Combs is leading this category this year- but Reese has been hurt). Another thing, Reese slows the game down by dribble up the court instead of passing ahead. For a PG he does not see the floor well and does not pass well, in the flow of the offense (my analysis). When on, he is one of our best shooters/scorers. So to limit the turnovers at the PG position and getting your scorers in a position with the defense running at them is optimal.
Now, the reason to have Holston on the floor. Holston at 6'7, is one of your best on-ball defenders (Brown is the other one), and only 1 of 2 guards on the team that can play D1 defense. That's his main role (I believe) when he's on the floor. Many times you will see him guarding the top scorers on the other team. His length makes it difficult for players to shoot over him. Watch how the other guards let guys go right down the lane and get our bigs in foul trouble or make easy layups.
Last thing- let's not go crazy on Holston over the new roll. We all know he's not a shooter, but to me, Holston looks up the floor much better and doesn't have the turnovers of the other guards. He needs some work on breaking down the defense, but judging by the Hartford game, he looks to be natural around the baseline and in the Sul Ross game, he had 6 rebounds from the PG position.