Case A is merely a probability calculation. On average, one would expect that you would have 56% chance to crit from sneak hit for each individual hit. However, achieving 100% crit rate is only possible with 10 werewolf cards (guarantees a back attack), else it’s all just luck.
Case B, I assume, is how it actually works, giving the probability you find in case A. However given that I have already learnt the dagger attribute I can’t really test it out.
The actual probability calculations are a little more complex.
Taking your scenario:
Base critical chance = 40% (for simplicity’s sake)
Sneak hit level 5 = 70%
8 werewolf cards = 80% chance of back attack
Chance of critical:
One of the cases:
Base critical chance did not work and werewolf + sneak hit works, or
Base crit works
If base crit works, doesn’t matter if werewolf proc or not.
Giving us:
(0.6 * 0.8 * (0.7 + 0.4)) + (0.4) = 0.928, Roughly 92.8% critical rate on average.
[Edit: Added basic crit chance to sneak hit chance assuming they stack.]
Perhaps someone that actually tested out the nature of werewolf cards + sneak hit could point out any flaws. This is all just theory, after all.
Edit: I do not know if having werewolf card forces each attack to be either front or back attack or not. The calculation might turn into:
_(0.6 * 0.8 * (0.7 + 0.4)) + (0.2 [Werewolf card failing] 0.4) = 0.608, Roughly 60.8% critical rate on average._*
Edit 2: Also not sure if Sneak Hit and Basic Crit are independent or not.