"Do you think training is child's play?!" Chen Yu glared at her fiercely, "Mo Shangjun, this isn't kids playing house. Business is business. If you have issues with someone's training methods, you should openly voice your opinions, there's no need to play these unprofessional little tricks! If you create internal conflicts, won't the cadets see it as a joke?! This is the special forces, it's a selection process! You need to understand the seriousness of the situation, this isn't a place to hang out with the cadets!"
The previous issues with Mo Shangjun being parachuted in have now evolved into criticisms of Mo Shangjun's lackadaisical approach to leading troops.
He, of course, leans more towards Yi Hui's way of leading.
In other words, he believes Mo Shangjun's leadership doesn't qualify as leading at all; it's just playing around, and such an attitude in a grave and serious setting... is completely inappropriate!