I'm be honest, if Pantheos theory with Kid is true, I can really see that happening.
- What if Kid mistakes Shanks to be Shamrock, who wrecked his village in the past
- What if Gunko is truly his childhood friend
This would explain why he was soo focused to fight Shanks.
He hated him(Shamrock) for what he did with his village.
Out of all Supernova, Kid is the most important one for Oda aside Law.