...he's actually not seeing it offhand, if he uses a random number generation method that they can't plausibly predict. And picking a random random number generation method that then uses some environmental entropy seems like a pretty powerful way of doing that even in a low-tech environment that's reading your mind.
For that matter, if there is some very clever way to defeat the proposal, he shouldn't think of it now, he should think of it afterwards. Maybe Asmodia asked that as a last-ditch desperate attempt by Conspiracy to make him think of a solution to a problem they couldn't solve themselves, though, also to be fair, that's sort of a nitwit clever tactic he can't see Conspiracy Asmodia actually being reckless enough to try.
Okay. Let's try that then.