Tongo
Journeyman Pro
I wish i had a suspect temperament that got me multiple wins and inside the worlds top 50 like those guys. Even better if it was one of those really dodgy temperaments like Rory, Rahm, Hatton or Casey that gets you into the top 5 players in the world over the years
The question was about who is most likely to win a major not who can make the top 5 of the world rankings. Luke Donald managed to get to world number one without ever really challenging for a major. Winning a major is a different kettle of fish. Of the four you've quoted, only one has won majors and the last was 7 years ago. Since then Rory has flattered to deceive in the majors with only decent final rounds adding some respectability to mediocre performances over the first 3 days whilst Casey has faded in the final round each time he's been in contention at a major. Rahm looks like he's going to explode any time he misses a putt. Hatton also looks like he might have a short fuse. There's plenty of players who have made the top 5 of the world rankings without winning a major.