I've interested in all sorts of books meant to improve your general understanding of human psychology and also all kinds of strategy/war tactics books.

So far I've read "The willpower instinct" and "The art of war".

I've heard that these books are good as well:
– The Prince
– The Art of Worldly Wisdom
– The 33 Strategies of War
– The Craft of Power

Perhaps you could suggest something more related to small squad based tactics?