The origin of the sentence "There are no soldiers who cannot lead troops well, only generals who cannot lead them" is not certain, but its meaning is similar to some ancient allusions and proverbs.
For example, Li Jing, a famous general of the Tang Dynasty, said in "Questions with Li Weigong": "The appointment of talented people is the foundation of running an army. Only talented people can be appointed, and there are no talents that cannot be used under the subordinates." This sentence expresses the same truth, that is, a good general should be able to discover and utilize the talents of his subordinates instead of complaining about their incompetence.
In addition, Jiang Wei, a famous general of the Shu Han Dynasty during the Three Kingdoms period, also had a famous saying: "If you use people for their strengths, there will be no people who cannot be used; if you use people for their shortcomings, there will be no people who can be used." This sentence emphasizes that generals should be good at discovering and capitalizing on the strengths of your subordinates, not their weaknesses.
In short, these ancient allusions and proverbs emphasize the leadership ability and employment skills of generals. A good general should be able to discover and utilize the talents of his subordinates to achieve the purpose of defeating the enemy.