That's a very good question. Similar to some words in English, Senjutsu has more than one meaning in Japanese and Chinese. In the military, senjutsu is a word used for military tactics, more specifically used in Military Colleges. The reason the word is used for multiple instances such as this comes from the fact that Senjutsu, which refers to Sage Arts, is the study of martial artists seeking true enlightenment, so the perfecting of true military tactics falls in line with the belief that a perfect mind makes the perfect man.