More dimensions does not mean more variability in abilities. The guys who can't do them very well don't make it to the big league unless they rake. I know that people want to add in crap like being a field general or really good at pitch calling is a real thing, but it's BS. The bench sets the D. Either directly or by relaying it to the catcher who sets it. The only time they're the field general is when they're shouting out cutoffs telling an infielder they can cut down a lead runner. The pitch calling stuff is covered in extensive meetings with the pitching coach and pitchers where they get scouting reports on opposing players. Catchers that aren't good at remembering reports don't make it far. Pitch framing is probably real, but would take a massive amount of data because of all the crap data - blowouts, 3-0, 0-2, etc - and seems like it would be highly volatile anyways. Catcher isn't a position where you can fool coaches like a fast outfielder or steady handed infielder can. If you can't do it you're not long for the league. It's why guys like Henry Blanco play into their 40's.