in a conjunctive case, such as cryonics, the more finely the necessary steps are broken down, the lower you can manipulate a naive estimate.

Except that people intuitively average these sorts of links, so hostile manipulation involves negating the conjunction and then turning it into a disjunction - please, dear reader, assign a probability to not-A, and not-B, and not-C - oh, look, the probability of A and B and C seems quite low now! If you were describing an actual conjunction, a Dark Arts practioner would manipulate it in favor of cryonics by zooming in and dwelling on links of great strength. To hostilely drive down the intuitive probability of a conjunction, you have to break it down into lots and lots of possible failure modes - which is of course the strategy practiced by people who prefer to drive down the probability of cryonics. (Motivation is shown by their failure to cover any disjunctive success modes.)