You just picked up your brand new sword from the smithy in your liege lord's city, and it's an expertly crafted blade. It holds a razor-sharp edge and is perfectly balanced for you. Your lord commands that you move to head off an enemy advance in his lands, and you ride to battle.
You're facing a knight in heavy steel armor, and you both swing and bash at each other with your swords. In the end, it boils down to an endurance test. The sharpness of your blade means nothing because you're swinging it against resilient steel, and your razor edge eventually grows dull. Your fine slicing and dicing weapon has become essentially a club, and your only lethal option is thrusting into a weak spot in your enemy's armor.
That's medieval combat. You swing and bash at each other, trying to tire out your enemy. When they're tired and stumble or make a mistake, you take advantage and incapacitate them.
Here's M&B combat.
You just visited Rivacheg, and you picked up a balanced bastard sword from the weapons merchant. King Yaroglek tells you he needs 87 sumpter horses, and he needs them now. You start travelling from town to town, and you pick up all of the sumpter horses you can find. You come across some pesky Swadians and decide to slaughter them mercilessly. You ride into battle, and everyone dies in two or three blows from your sword. After swinging maybe 30 times, you and your party have killed the Swadians.
That's M&B combat. Your battles don't last long enough to deteriorate your weapon any significant amount, let alone break it. Your weapon is only going to break if it's poorly made, poorly treated, incredibly old, or a combination of the three. Polearms could break, yes, and I can imagine many spears were cut in half by axes and large swords, but to make only spears break would be horrible.
