Honestly, when it comes to the captaincy this game is a bit of a game theory nightmare. Like one of those theoretical games that John Nash came up with like "Fuck You Buddy" or "So Long Sucker." If you want to keep the captaincy of this donkey show of a mission you have to be pretty ruthless. The safest path is to buddy up to the killer AI and kill Justin when you have the chance if you have the balls. You also have to fuck at least one of the two girls that are not your girlfriend. It gets tougher because many of the characters are package deals. To get Bruno you need Delilah, and you will notice he is the least common denominator in every scenario where you are ousted. So you better fuck and share her like you are trying to win something. Because you are. If you let Justin bang both Delilah and Gabrielle and EJ is against you then you are in deep shit. You better have addressed Jack's concerns in any scenario because he is a crucial swing vote. It does seem like there is one crew member who will vote for you no matter what even if you don't vote for yourself, so you have that going for you. If you do let Veronica slip through your fingers the chances of you accumulating 4 votes is really dicey, because you will slip into the cuckolded path with all the girls. In this realpolitik version of marry/fuck/kill where those who are too curious get murdered and reprogrammed it is easy to forget that this shit matters at all. However, it really does if you don't want to be Justin's fluffer for the rest of your life.