Something always bother me about training pics involving PLA(N) personnel like this one. I can't point to what it is. Seems to me they lack focus/spirit and are just posing for the photoshoot.
That is probably because this wasn't an 'action shot' taken during an actual exercise. The photographer almost certainly staged this, and the marines/SOF guys were probably uncomfortable doing it and/or very bored and tired after how ever many similar shots.
You see nothing like this on videos of PLA personnel training, and that is what really counts. As long as they know how to do the business when it matters, it doesn't really matter how bored/demoralized (which they probably are there!) they look in some staged propaganda shots.