Luffy's using Rifle and Gattling versions of G4 techniques without drawing blood, do you legitimately think Kinemon's attack packs more attack power than Luffy's attacks ? That they'd cause nearly the same amount of destruction ?
I don't think it's even a fraction of that. Kinemon has a good technique to cut through something very durable, but in terms of actual attack power his not even in the same realm as G4 Luffy's attacks.