I'm not sure about 3 scum unless Town gots more power roles.
Once I saw the problem emerging, I said something, but now its something that people have to get more of a habit with. Lurkers are a plauge on the town and won't help the town even though they win with town. Mafia isn't going to go after somebody who isn't a threat to them, so even if they town, they are not helping to win the game. Many players post more frequently then others game after game. some when they do post post 1 to two words hiding under the radar. There are ways to get this sort of behavoir sorted, as players we can only do so much. I came from a board that awarded good activity. We only ussally hade 3 days to decide who to lynch if anybody. But if activity was really good, say 40 posts day 1, 30, day 2 or something we get more time. However posts that are only a few words wouldn't count towards getting that extra time. If discussion wasn't happening, inactives would be purged as they didn't help towards the end goal. just some thoughts out there.
right now I got Isoc and TW on my short scum list, but that could change very easily since its day 1 still.