Archers would be forced to use higher armour. Surely it should be the other way around anyway due to the fact that you can carry more weight while wearing less...?
I'd hate to just become a pack horse over the logic of "You're already carrying heavy stuff, thus you should be able to carry more!"
I know where you're coming from with like "pockets", more expensive armour, more pockets, but i'm not sure it would work for balance reasons.