I can tell you they aren't the brightest and the best. Airline pilot isn't a prestigious job in China. All of the cadets told me that in the last year of their engineering degrees (all studying in China) they sit aptitude tests and pretty much get told what jobs they are going to be placed in. None of them wanted to be pilots.
I can vouch for that. Many years back I was involved training Chinese pilots who were learning to fly at Massey University in NZ. I asked some of them how they got into flying. They said they were given no choice. All were studying various disciplines at a Chinese University when "the authorities" arrived and directed all students at a certain level to undertake flight crew medicals. Those who passed were further streamed into would be military pilot training, while the rest were to be airline pilots eventually. One student was knocked back from pilot training because he had buck-teeth which was considered not a good look for a pilot. I saw little signs of enthusiasm for flying from these cadets.