This is true in technology-based forces like the ones common in Europe, where better equipment wins battles. But this is feudal Japan, a land where the metal is of terrible quality and the folding technique had just recently been invented, was extremely time consuming, and was reserved for outfitting nobility. Most combatants didn't even have armor except for maybe a basic breastplate, and a lot of them fought with simple, light spears. No commoner was carrying anything into battle except a three pound stick with a pointy end.

Also, I never said that women took part in sieges or raids. Most of the battles they fought in were defensive. No tents or rations required.