Like DodgyPutter said, the 750 ranked rounds must all be played from when you advanced to the Tour Legends tier, not from the total RR’s you played from the start of joining WGT. There is also another way of tiering up if you play in the coin rooms but that’s a mystery to most of us on how it works.
Also play the game the way you want to play, don’t worry about others trying to tell you how they want you to play. This game is all about just having fun, some people just take it a bit to seriously. Have fun and enjoy.