There aren't 7 players alive, there are 10, with a possible doc in the mix.
Using the usual formula of floor(numPlayers/4) yields 3 scum, maybe 4 if town is stacked with power, but there has been enough power in the flipped roles to rule out a 2-man scumteam
Vengeful Spirit is potent as hell--that's the role that snatched victory from the jaws of my incompetence in a game I was in a couple years back