Astarogh, I like your idea but I suspect a fair number of replies you get are going to be "Being a Privateer is kind of like stealth, you can go and kill every Drengin ship in existance and no-one know it was you." Let's face it, killing/undermining enemies without being uncovered as The Killer is basically The Reason for having stealth in any game. You don't have stealth in Sims games, after all, do you?
In other words, the stealth mechanic is already there. It's just called Privateer with a skull and cross icon on your Privateer ship/ships.