I am not so sure Merlino would have won. Maybe Stanfa wasn't a good boss, but still the fact remains Merlino didn't manage to actually kill even one of Stanfa's men (at least the murders he was charged with weren't related to this specific war, as far as I know). He only tried to, but always failed. Maybe, had the feds given Stanfa more time, he would have been serving an additional (sixth) life sentence for Merlino's murder now.