I doubt this will be the case against skilled players. Archers usually have to fight with extra weight (10.0 per arrows), which will make them worse in footwork. If the melee mode doesn't even have a chance to stagger at all, it will be pointless. Yes you can stagger with 15b, you can even kill someone with it. But good luck killing an infantry with a weapon that does as much damage as a cudgel (1h mode) and can't be used to block.
I think it'd be ok if archer can nudge and kick someone after chamber... It's kind of last think what you can do if there's no time for changing weapon. It's just a funny feature, it doesn't need to be really effective and changing the balance... it just makes the game deeper in some sense.