I dont even know why people care about scaling Shanks anymore. Ever since he was revealed to have an evil twin brother, there was absolutely no agency in thinking he'll ever fight Luffy seriously now. Sure, his 1054 scene about finding One Piece is still odd but even then, his relationships with Roger's crew is pretty telling then.
All we can hope for is Shamrock being presented well in this story for someone, hopefully Luffy, at a key moment. Fingers crossed its still this arc...