Whitebeard to Shanks when first meeting him in the Manga on his ship:
"Just seeing your face makes the wound given by that bastard ache again"
At first people thought this meant Roger, then Garling. But if his bro is Shanks twin and looks EXACTLY like him would it not fit Shanks brother much better?
Like, sure, young Garling looks kinda like Shanks, but if Shanks bro is the one that met the Gorosei he is an exact copy of Shanks. Perhaps a young Garling could have given Whitebeard his scar?
Not THAT insane at all to me if Shanks was out here learning Divine Departure as a Cabin Boy, who knows what Garling could teach his bro when preparing him to become a God Knight.