I think, like hit points representing skill at higher levels as much as ability to take punishment and armor is a binary effect (Hit or not Hit) which is the opposite of combat where armor can slow you down but add the benefit of absorbing impact, weapon speed is just opens up a whole can of worms. Yes, a dagger can attack more quickly, but it's much less effective at blocking heavier weapons, and the act of trying to get inside the swing is basically risking an attack of opportunity. Rather than all this detail (which was sort of in the 2nd Edition Players Option rules), just get rid of weapon speed and imagine the combat how you want.
