Chance of getting hit by a Cop or by mafias NK are the same, but:
- Cop is way easier to be eliminated ( hes just one and you need to kill all 3 scum to stop NKs).
- Cop can be switched off (almost certain). Mafias NK cannot.
Adding Vig to the equation makes town theoretically more dangerous ( 2 actions vs 1), but again he can be switched off (less likely) / killed or simply not want to shoot blindly.
However if SK choosed town immunity, then indeed he can mess with mafia and make Cop more usable. But should we gamble on that and go no lynch patch? I dont think so ( cops not going to find every scum for us).