Ooops, looks like I missed the game. Oh well.
fwiw, Bang! suggests that a good balance is this:
3 players: 1 Sheriff, 1 Renegade, 1 Outlaw
4 players: 1 Sheriff, 1 Renegade, 2 Outlaws
5 players: 1 Sheriff, 1 Renegade, 2 Outlaws, 1 Deputy
6 players: 1 Sheriff, 1 Renegade, 3 Outlaws, 1 Deputy
7 players: 1 Sheriff, 1 Renegade, 3 Outlaws, 2 Deputies