Sprinting and marathon running are entirely different sports requiring totally different physiques and training methods, even if they are built around the core aspect of running.
Curry is world class because he can perform at his best for 4 quarters. If the could only shoot lights out for one quarter, he wouldn't be a star. And a reliever in baseball is not a world class starting pitcher, which I was referring to in my example.
Every other major sport, and even pool's cue sport cousin snooker, structures matches at a length that requires stamina over 2-3-4 or more hours and sometimes days, like golf tournaments (I know pool tournaments can last a couple of days, but scoring isn't aggregate).
Races to 25 are fine for this regard, so if Ko can indeed beat Shane the majority of the time in those matches, I would consider him the better player.
I'm indicting short races to 5,7,9. Winning over that short a term means little. The best players will still reign supreme of course, but we never really "know" who is the best at the end of any given tournament year, since 10-15 players are all capable of getting hot and capturing the number one ranking. Albin is now the "number one" player in the world (per WPA) shooting up from 8 after his China Open win. You'd never see a player shoot up 8 places in the tennis or golf rankings after a single win.
I want to see pool structured in a way that sees a player dominating the number one ranking for years, like tennis or golf, or even during pool's 14.1 heyday (tournament play was more demanding back then. Round robin formats in addition to the fact that 14.1 is less luck based than the rotation games).
Just like Fast Eddie said in The Color of Money about tournament play, "It goes in streaks."