Do not engage an enemy more powerful than you. And if it is unavoidable and you do have to engage, then make sure you engage it on your terms, not on your enemy's terms.
Sun TzuThere are five kinds of incendiary attack: The first is called setting fire to personnel; the second, to stores; the third, to transport vehicles and equipment; the fourth, to munitions; the fifth, to supply installations...In all cases an army must understand the changes induced by the five kinds of incendiary attack, and make use of logistical calculations to address them.
Sun TzuThere are roads which must not be followed, armies which must not be attacked, towns which must not be besieged, positions which must not be contested, commands of the sovereign which must not be obeyed.
Sun TzuWith regard to narrow passes, if you can occupy them first, let them be strongly garrisoned and await the advent of the enemy.
Sun Tzu