He has by far his most appearances at 4th, so the other lineup spot appearances are very low sample sizes, but you are right. His worst OPS by a wide margin is when he’s 4th. If I had to guess, the thinking by CC is that he doesn’t hit into a lot of double-plays and he doesn’t K much, either. That batted ball profile could, over time, play better in run-producing situations than guys who have been striking out there a lot (anecdotally, I’d point to Adames and Tellez as major culprits on this front, but I’m too lazy to check the stat page to confirm).