I would agree with this if you changed "ridiculously rare" to "rare" and removed "not worth entertaining."I just assume it is ridiculously rare to lopsidedly improve your shotmaking and not also bring your cueball control and patterns up too. I’m thinking the weak ball maker with good compensating skills that ends up equivalent in FargoRating/wins is more of a unicorn not worth entertaining. The pros we call great shotmakers (and still live up to it) seem to me that they are better at pretty much all aspects. Filler? Fedor? Shaw?
You are describing the concept we call "skill equilibrium."
When you are a 600-rated player and you roughly have the shotmaking of a 600, the safety play of a 600, the speed control of a 600, we say you are in skill equilibrium. Contract this with the 600-rated player who has the shot-making ability of a 650 but who makes strategic decisions commensurate with those of a 550-rated player (go for the out too much, miss two-way opportunities, choose wonky patterns.). Though we all have someone who comes to mind here, this really isn't very usual.
Our experience is most players are roughly in skill equilibrium. When you think of a snooker player starting to play rotation games or a player going from a 9-foot to a 7-foot table or from a 7-foot to a 9-foot table, players are out of skill equilibrium. But the next 50-100 hours with the new game or new environment tends to reestablish it because the things you are temporarily bad at in the new environment tend to improve faster as you play, bringing you toward skill equilibrium.
An aging player with deteriorating fine-motor skills might be out of skill equilibrium. A top young shooter from a small town with limited exposure to top-level competition might be out of skill equilibrium.