I’d say it’s more akin to a renowned soccer player switching over to rugby. Could it work? Yeah. There are elements that would definitely carry over across sports. But keep in mind that it is, in fact, a different sport.
There’s also the aspect that just because a coach/program is prestigious doesn’t mean that it will be the best fit for the athlete. I’m sure Saenchai could stand out at any MMA gym, and I’m sure that Zahabi and the fighters at TriStar have the tools to vastly help the aspects on which he needs improvement in order to compete in the UFC. But that doesn’t mean that TriStar will be the best option for him.
Also, Dieselnoi and Samart might object to Saenchai being arguably the greatest.