@Bogard
So Ace was even to strong for Jinbe and his CoA. With proof why Van Auger respect Ace,he was not only strong because of his devilfruit but overall.
So take this in mind:
Ace fight equal with Jinbe and even won(he stand up and fight Whitebeard while Jinbe was still down)
He clash against Yamato equal, she daughter of the strongest beast.
That all BEFORE he join Whitebeard and sail for 2years with WB. Ace was easily YC lvl,his control with CoC,he had CoA before even beating Jinbe and even had most like CoO.