@Count:
That was my EXACT thought process when watching the scene as well.
All this scene makes me think about is how much I would love to see more overseas battles in One Piece lol. I often see that as a complain from people. The only one that comes to mind recently as the Curly Hats fighting Big Mom's ship.
You know it's quite ironic that someone named Jack would be the one to bring the naval battles back into One Piece. That's definitely something that needs to be touched upon more but I think the nature of such battles, especially if it involves the Sunny would realistically mean that the ship would be blown to bits. Don't you ever wonder how such a slow huge moving target manages to evade numerous cannon balls, I mean I know the marine scrubs have a big problem with firing things in general (just look at how they fire rifles at people they magically miss a stationary target). The sunny is equipped with it's coup de burst to avoid such situations. I don't think the writer knows how he wants to handle battles like this at sea. Whereas, with marines and other pirates it's easier to portray I suppose. If that's the case then I would welcome more battles between non strawhat pirates and marines because they're so epic. Would have loved to seen how Jack took out 2 (or was it 3?) out of the 4 ships.