I’m in the first part of Churchill’s biography of the Duke of Marlborough, Marlborough, written in 1933. I was taken by this passage (especially as it was written pre-WWII):

“It is customary to say that he [Marlborough] learned the art of war from Turenne. This is going too far. No competent officer of that age could watch the composed genius of Turenne in action without being enriched thereby. But no battle ever repeats itself. The success of a commander does not arise from following rules or models. It consists in an absolutely new comprehension of the dominant facts of the situation at the time, and all the forces at work. Cooks use recipes for dishes and doctors have prescriptions for diseases, but every great operation of war is unique. The kind of intelligence capable of grasping in its complete integrity what is actually happening in the field is not taught by the tactics of commanders on one side or the other—though these may train the mind—but by a profound appreciation of the actual event. There is no surer road to ill-success in war than to imitate the plans of bygone heroes and to fit them to novel situations.”