We also see panels when Pizzaro graps on his head and the hand is comparable to the skull. And the skull is hardly relative to the battleships when it dwarfs TB.
Where is the issue lol?
The panel can be drawn over 200 or 300 chapters ago and it still can be used for scaling. It only destroys your narrative, that's why you are disregarding it.
You say the mangaka is inconsistent with the sizes yet you believe the arm is building sized (which itself is a massive L take). So you do use some sort of scaling to base your opinion like that, is it not?
1.) Many users here even downplayed Koby prior to this chapter, so nice try with the ad hominem.
2.) Koby is factually not a pink failure; dude has started training for 2 years and he already starts replicating Garp's technique.