Hmmmm....
I am not sure about Astro and d8p, but I find it hard to believe that scum could build cop units, so either Astro is telling the truth, or Vismaior was scum with him (that would have been quite a gambit!).
That last possibility would give us a 4 person (or more) (2 dead + Astro and d8p, at least) scum group, able to build killing units.
Otherwise, if there's two scum groups, I would guess that none of them would have more than 3 people, so Astro and d8p couldn't be scum with the european barbarians.
I would say that the night events suggest the existence of 2 scum groups, so I would be inclined to trust Astro and d8p even if I can't really understand why d8p got a result on Yos that doesn't match Puzzle's one.
I would say that's a sanity issue more than a possibility-of-being-scum issue anyway, and lynching Lord Rahl would probably give us a better understanding of the situation.
vote: Lord Rahl