since the post was closed for some reason, ill edit.
i saw the post about all the mess with blocking an attack but holding the striking surface of a blade. i can understand this if they do have the chain gloves from the historical accounts.
otherwise, you've given people an unbreakable shield that you can strike with; ive seen it done, last sunday actually. block several hit then strike.
and yes weapons are smaller than shields, but anyone with even mediocre blocking ability can handle it. you dont lose noticeable offense because NO ONE keeps 2 hands at all times, they hold it long enough to deflect then they strike. they wouldnt do it if it didnt offer an advantage...
and your last part, it yes its easier to swing around, but with a sword weighting much much less than a shield, the speed more than makes the difference.
we're of course talking about higher level fighters