What if the chances were changed to:
Body: 20%-30% (depending on size)
Legs: 10%
Feet: 5%
Hands: 5%
Shield: 10%-20% (depending on size)
Weapon: 0%-10% (depending on difficulty)
TOTAL: 80% maximum chance to block any one hit, assuming full equipment.
You could train your weapon or shield up to 20% and 30% respectively with <Weapon> Expertise, making a total of 100% chance to block any one hit. Now bigger armour is a lot better!
indeed but we're talking about a parrying ability here... 100% parrying ability would mean you would NEVER get hit in the side with a mace as long as you're still armed with a shield or blocking capable weapon...
No, because blocking with your weapon or shield only counts for up to 50% of your blocks. The other 50% is made up of bodily armour. Any hit that lands on you has a chance of hitting a piece of armour or finding a chink in it. You can add an extra layer of protection with a weapon and shield. So if they get past the weapon and shield, they then have the armour to deal with. Hitting the armour still hurts the character. If they manage to get through that, they are very lucky!
Looking now, take another 5% off the Shield so that you do not become entirely impervious.