Royce has been our PF more than Brooks. Hes shooting considerably better than Grayson and has stayed healthy. Royce is hitting 3's at 42.4% compared to Grayson at 37.9%. Royce has played in 39 games, starting 35, to Allen's 22, 18 starts. Royce is also #2 in boards per game behind Williams at 5.1 a game but Brooks is at 3.3 and #9, behind Goodwin and Collin.
I can see the creation side in favor of Grayson but bringing him off the bench should keep him healthier, allow him to exploit more mismatches and bench players, and give him more looks.
I think Royce is a less troublesome Jae Crowder for us. He's not a traditional PF but next to a legit C like Williams and with quality rebounding guards in Book and Collin plus Brooks disrupting things, he makes it work.