Until we don't know for certain whether the 'Shanks' we saw talk to the Gorosei was indeed Shanks I'm not going to pass my judgement yet.
This one point would change everything about Shanks' personality and his role in the story.
This one point would change everything about Shanks' personality and his role in the story.
we know that he's from a celestial dragon family, Sengoku stopped the war because it was him, Shanks has access to privileges that no pirate does.
He also came to the Gorosei to talk about "a certain pirate" that's definitely Teach.
And if it wasn't Shanks, and instead it was his brother "Fhanks", why would the Gorosei tell a Holy Knight that he "should have nothing to do with politics"