No offense, but this is quite an flawed argument for Guts's favor.
Do note that I am not casting my votes yet in this matchup, I'm just addressing the arguments and what I think of them.
Guts has shown a far, FAR greater degree of stamina and determination than Deku, constantly fighting against Apostles even when broken and bloodied
It is true that Guts may have better stamina, but this is a one-sided argument that doesn't even address Deku's capabilities, even if it is true that Guts had a much worse situation than Deku did.
Constantly fighting even when broken and bloodied... isn't something to be proud of when comparing to Deku, somebody who fights with all of his limbs broken and suffering attacks of similar magnitudes as his own.
Constantly fighting is also something that Deku had to go through during the "Dark Deku" arc, where it was stated that he had extremely minimal amount of rest, fighting villains on air, water and land.
even hacking his own arm off without any visible signs of pain
Deku breaks his own arms all the time. It's different from stabbing your own arm, but I'm not really sure how this is something that would be relevant in the fight, as both of them are willing to harm their own body and keep fighting.
He's even let himself be injured in order to get an opening for an attack.
Same as above. This literally applies to Deku as well.
Not only that, but Guts has been fighting his entire life: he's faced many more enemies than Deku ever has and is a master swordsman
This is true, like I said above. Guts has the battle experience advantage so I agree, but it's not like Deku is new to fighting to death either.
who is also skilled in different fields of combat such as knife throwing, his arm cannon with different weapons, and even his miniature explosives. Deku has also never fought a swordsman before, so he has no idea how to properly fight against one.
This one is
completely false, courtesy of
one of MHA's most popular villain. Who happens to use swords and knife throwing. Aside from that, he has experience fighting against a
girl with knives and other stabby things,
a guy who sprouts really sharp spikes from the ground, and
a guy that makes explosions, as well as
an assassin that uses a sniper that fires what is essentially a cannonball in terms of bullets.
Deku wouldn't be bewildered fighting a swordsman at all.
As it stands, Guts has the advantage on experience and possibly endurance, but the latter doesn't really have much of a gap. Serpico did pretty well against Guts and he has nowhere near the experience nor endurance as Guts (and Deku especially with endurance).