Everyone is good at rapier, you just stab stab stab and there’s not entirely much a person can do to it
if the rapier dude is mindlessly attacking (not even gambling, just spamming) a riposte from even a maul will out-time it. If rapier-boi is extra dumb that will give you a nice meaty whack, if not a feint-to-parry and you will decimate their stamina.