Not sure I actually agree that the movement penalty is too harsh. I had collected enough +movespeed items, later in the game, to ensure that both of my warriors' movespeed was greater than 3, anyway. They were essentially Quicksilver and the Flash, speeding around in full plate.
I personally think that if your character is gonna wear plate armor, you just gotta accept that they're gonna be .7 slower. There's ways to boost their speed back up, anyway, not to mention phoenix dive and bull rush.