I came here this morning to start a conversation about this. Haven't had time to respond.
The contrast in their game couldn't be sharper. Rozier is explosive. He can score in bunches, slash to the rim for a dunk, hit big threes, get key steals, and soar for defensive rebounds.
But his feel for the game has always been wildly lacking. Sometimes he looks great. Other times, he doesn't.
Wannamaker, on the other hand, is more steady. His feel for the game is superb for a bench guard. I don't think he can make the same kind of explosive plays as Rozier, but he is a much steadier option to run an offense.
Under Wannamaker the offense is more likely to get consistent good looks and less likely to go on a huge run. Under Rozier the offense is less likely to get consistent good looks and more likely to go on a huge run.
I haven't seen enough of Wannamaker to confidently think he could play a JJ Barea role, but maybe he could. I've seen enough of Rozier to want Brad to put him in for 4 minutes and see if a few shots fall. Bench if they don't and play him longer if they do.