Armor Characteristics

Does anyone understand the armor characteristics? Corwen in Ascalon needs only 6 iron for the Ring Mail Hauberk. For the Ascalon Curass it's 12 iron & 3 fur. But the Hauberk looks better, Armor 50, Armor 20 against physical attack. Where as the curass is 50 and 10. Am I reading something wrong? Why would I ever get the Curass? Is ther somewhere I can get an explanation of what these weapon and armor numbers mean? How does different armor values for different pieces of armor combine overall?

Game Mechanics

Don't let his genius math skills confuse you. It is really simple to follow on the more broad aspects. And to note, there is no overall armor total. Each piece is counted seperately. Just read and you should understand.

So i'm better off with the ringmail hauberk. It costs less metal, no fur and it's tougher. The only advantage of the hauberk is it's more stylish.