I dont buy that guy's reasoning for not killing the 4 potential prophets at all.
Going with their current assumption of having up to 2 werewolves (ww) pretending to be prophets, they would have a 1/4 or 1/2 chance of killing a ww, versus a 1/4 or 1/8 chance in choosing from the remaining 8. I'm confused why they are even voting from the other 8 at all. Even in the worse case scenario of none of the ww are faking, they are still taking out fake prophets who are giving false information and sabotaging the game. Divining the fox doesn't matter if they just lynch her too.
From my experience, any prophet getting killed to bait out even 1 ww is mvp material already.