Degree. Imagine three or four sentences, if Xiang Yu returns to Jiangdong and regroups, maybe he can make a comeback. This sentence has some pity for Xiang Yu who committed suicide in anger, but the main meaning is to criticize him for not being good at grasping opportunities and listening to others' construction.
Discussion, not good at employing people. Sima Qian once criticized Xiang Yu's stubbornness of "killing me by heaven is not a crime of war" from the perspective of historians. Du Mu, on the other hand, talks about success or failure from the perspective of a military strategist. Both of them pay attention to personnel, but Sima Qian summed it up.
Learned lessons and emphasized the reasons for failure; Du Mu is an imaginary opportunity, emphasizing that military strategists should have foresight and indomitable will.