Isn't that for throwing? You said that gauntlets were too heavy for archers.
For what I've understood, the effective weight is the weights of 
headarmor*3 + handarmor*2 + bodyarmor + legarmor.
 And the wpf penalty starts running from 7.7 onwarnds. 
I could be horribly wrong, but at least I'm giving you free bumbs 
