I find cooperation with cooperation-bot utterly insane in context; I would have predicted less than three, but a good chance of at least one. In the real world problem, or a tournament with a lot of rounds, it's potentially worth saying that since C-bots will die off quickly (although, if enough people cooperate with them, maybe they won't) they're effectively unlikely enough that you can safely use your response to them as signaling for other programs, but if that's true, then your opponent should presumably know that and throw non-trivial cases at you instead.