I’m don’t think I understand the question here… ;p
I’m going to assume you are asking Yun players which type of style they have the most trouble against.
The toughest challenge for Yun (at least for me), are the ones who stay in your face. They jump when u jump, and the stay on the ground when you stay on the ground. outside of GJ, yun is definitely at a disadvantage in terms of priority.
Turtles are pretty easy to topple over with yun. As long as you can stay on top of your opponent, especially with dive kick > s.mk x sj cancel > blahblahblah.
Parry happy players tend not to do well in any aspect of the game. Parrying is risky and should only be done if you absolutely KNOW you will get a parry and an advantage afterwards. I used to be parry happy, and I’ve been taught and told to just block ^^