I'm not sure if just having a performance coach is what makes such a difference. I think it's also possible that panda is just exceptional at his job. Paper rex used to be one of the teams with the worst mental in the world. They had choked so much that the pressure must've been wild for them especially with the same core for 5 years. Panda joins and instantly within a few months they are now the team with the best mental in the whole world. They can go down 0-4 or 0-6 and think its fine we'll win the next 6 or 10 rounds. That's insane if you ask me.
It also helps that the org is insanely competent and makes sure the players don't have to worry about anything beyond performing. They seem to get very good breaks and seem to handle their personal life very well also.
Another fun fact about panda is that he writes personalized notes to each of the players in their mother tongue. He even writes them in russian for something. In an international roster that must make such a huge difference. The dude is just a class act.