I don't even see the comparison between Luffy and Hancock and Goku and Chi Chi. In Dragon Ball, Goku won Chi Chi's hand in marriage sort of by the way, and she became enamored with him and eventually chased him down to force him to fulfill his "promise". Goku basically didn't wanna renege on a promise, so he went with it. Here, Luffy did absolutely NOTHING but impress Hancock with his willingness to defy the World Government, and she's become so lovesick that she's physically ill. The difference is, there's an actual disease this time, and there's nothing for Hancock to hold over Luffy's head to force him to marry her, like Chi Chi had. Not to mention that considering the situation, Luffy can't afford to have a fangirl who is also a rival pirate captain, an empress, and a Shichibukai hanging around his crew fangirl-ing, Hancock wouldn't fit the crew. As of now, I'm keeping "Hancock joins" as the "Dumb Theory of the Month". About two months ago it was "Haki is All-Powerful", last month it was "Haki is All-Powerful/Marguerite Will Join", and we see where both of those have ended up as of now...