Luffy is mythical zoan wirh rubber body that resist blunt attacks better
Nice try comparing Garp (average durability)with Luffy lol
Btw Shiryu is also using a sword while katakuri using punches /kicks
I guess fodders > katakuri in AP since they can injure wb or garp easily lol
The introduction of Haki more or less removed all the technicalities from fighting in OP because it's just a matter of
"is A's haki stronger than B's". The days of Lufy only being able to hurt Crocodile with blood on his fists or Enel getting hard countered by Lufy's rubber body are long gone so I don't think that the chocie between swords, fists and bullets have any weight anymore since anything can be infused with Haki and this ultimately is what decides who comes out on top, save for Oda wanting the plot to develop however he likes.
Then again, I don't think it's worth trying to rationalize character powers like this in this particular story because everything is subject to the plot. A visible injury, broken bones or blood loss don't mean anything as long as it isn't the loss of a limb (and even that doesn't seem to impede Shanks that much, does it?). Sometimes an impaled torso kills, sometimes it doesn't. With cartoon physics and biology at play (regrowing teeth with milk, as just one example lol), these things can't reliably be taken into account.
At the end of the day, if an attack is fatal or not is determined by its outcome for the plot and not by what we have seen in the story so far or what would reasonably be expected to kill someone.
I know that doing exactly that makes up about 90% of posts on this site and it's a fun pass time for many I suppose but Oda just doesn't play by those rules. At least when it comes to the outcome of future battles that may or may not happen I wouldn't point to any past encounters and try to make sense of them - that's why it would've been a guess as good as any to call the circumstances of Garp's defeat beforehand.
Sure, there's usually some named character involved instead of some random dude or natural causes but that's about where it ends.
Sorry for rambling and this should probably go into unpopular opinions but eh.