With practical perspective, answer the question, the fight power comes from "mobility X firepower" not armor that was proved by Mongolian Horse Troops of Genghis Khan. lightweight, high speed with long- range weapon as archery against the spear or sword with heavy armored knight the enemy.
My research of "future mobility" adopted ancient art of war that there are bunch of theoretical example about psychological strategy most of them I can not use.
Additionally modular concept might be the useful art of war in theses days.
It is possible to make this even shorter, in one phrase of Sun Tzu: "The best is to destroy the plans of your enemy, to defeat his armed forces is worse, the worst is to sciege fortresses."
And here is the Sun Tzu - The Art of War Book Summary. You can find it on attachment...