Luffy was much faster than him and easily controlled the fight through CoO (except that one time he couldn't stop Lucci from piercing Sentoumaru's chest), but he was sent flying backwards the one time they clashed with haki, in G5. Why isn't Zoro, no bandana, no CoC, no Asura, flying backwards, and is instead pressuring Lucci?
It's easy to downplay any character this arc.