One word: enlightenment.
Strategies are by no means copied from textbooks and memorized by rote, but based on the actual situation, combined with textbooks, and applied flexibly.
Take the Three Kingdoms as an example. Sun Quan encouraged Lü Meng to learn from him and seemed to have given Lü Meng a list of seven books. Only two of them were military books, and the rest were history books. Military books are notes of insights, while history is a matter of benevolence and wisdom. Different people have different perceptions. The book of war is a method for us to learn insights and master some common sense, so Cao Cao wrote the insights into Meng De's book of war, Zhuge Liang wrote Zhuge Kongming's book of war, and Guan Yu loved to read the history of the Spring and Autumn Period...
Of course, some northern minorities The leader of the nation was very strategic even though he did not read much military literature.
But they have "natural" textbooks, and they have been exposed to natural selection in a harsh environment since childhood. What they imitate and understand is the cunning of foxes and the cooperation of wolves...