What Comrade Lao Liang said makes sense, but it is a bit nonsense.
The reason is: Comrade Han Xin is young but mature;
He has made every effort to figure out Xiang Yu's military behavior; he arranged for him to capsize the boat in the middle of the river and kill him;
But a general who leads an army of hundreds of thousands and considers a small boat is a little confused; why? Xiang Yu's bravery is unparalleled throughout history;
No one can predict which opening he will break through. It would take at least 5,000 small boats on the Wujiang River to wait for Xiang Yu.
But if Han Xin is so awesome, he will definitely brag among his buddies! Moreover, when Han Xin defeated Xiang Yu, he was in his twenties and still young and frivolous. There is no reason why Sima Qian didn't know about this strategy and didn't record it; history is made up of many accidents.
Personally I still think it was an accident, and the old man really helped Xiang Yu.