Yang Yi's biggest problem right now is that he can't command respect when acting as a leader.
In the Organization of Water, there are nothing but top talents from various industries. While Mike was alive, he would wholeheartedly help Yang Yi. Brian, to repay Yang Yi for his assistance, would aid him too, but they were helping Yang Yi, not taking orders from him.
Zhang Yong is an experienced old mercenary. He isn't a part of the Organization of Water because he must be, and he stays only to give face to Yang Yi.
Xiao Ran, the cleaner's mole and also a liaison, carries such significant clout. How could she possibly be genuinely subordinate to Yang Yi? She isn't convinced by him at all, not in her heart and even less so with her words.
The only one who advances and retreats alongside Yang Yi, sharing life and death, is Kate.
As for Tang Guo and Schultz, they both could fare well outside the Organization of Water, but under Yang Yi, they can get what they most desire.
