What is wrong with Luffy being exhausted from his first ever G3 Gatling?
Who said "being exhausted" is wrong? Luffy started to pant after blocking Decken's axe in the tower. There is an indescribably massive difference between "being exhausted" or "tired" and LUFFY being brought to his limit. He will "later" be able to do big moves when injured because he'll be "stronger"? Oh man. This is the guy who 2 weeks after entering the Grand Line beat a Shichibukai through a dozen layers of bedrock uprooting a city block with a hole in his stomach, certainly a very great amount of blood loss and stone-melting poison in his veins. He was so badly worn down he could hardly move, which was not just extreme injuries but also severe strain on his body from extended G2 usage, when he fired off Jet Gatling Gun against Lucci. And now it's okay if he's done for after using one attack just because it's a big one? That would take his growth, resolve and all that and stamp it into the ground if he has as little endurance as that. How incredibly low standards are we supposed to hold Luffy to after a whole series of precedent? He took ONE ATTACK. A single attack from an enemy that's way below him in strength, and then "putting in a lot of effort" brings him to the edge? That is a joke. Or else the Gears are certainly extremely, extremely, extremely damaging to his body.
Hody landed one hit, the rest was ALL damage from the effort it took using Gear Third. His wound wasn't even open before he used it. Are you really saying that using G3 Gatling for a minute is somehow worse than taking extreme amounts of physical damage, severe blood loss, much more exhaustion and according to some maybe even the strain of Gear stacking in a fight against a serious opponent on his own level? It's insane to say that it's even remotely comparable. One minute you say? I'd expect his big battles to possibly last an hour, the Lucci fight was 30+ minutes and Ace and Jimbei of course fought for 5 days though however much we'll be seeing that again I'm not sure of.
Point isn't that him passing out doesn't make sense under those circumstances. It made perfect sense and has as much as precedent as one could ask for. Point is he came nowhere close to his true, in-battle limit. He just let himself go to sleep because the job was done. Noah would have been destroyed if he kept at it and you saw how much there was left, that says enough about how much power he had left.