I'm taking a college class on Robert Greene's 48 Laws of Power, and for our last class we read the chapter on scapegoats, and relevant to this post, the Cat's-paw - a person who is used by another, typically to carry out an unpleasant or dangerous task.

He then made the point that ideally, your wingman shouldn't even know he's a wingman. It would have to be someone who naturally elevates your SMV. Now that's easier said than done, as there's a few things I think you have to watch out for. You should be more attractive than your wingman, but he shouldn't be someone so ugly people wonder why you hang out with him. You should also have better social skills than him, but again, don't bring your friend who won't stop talking about jet fuels and steel beams. This leads me to believe the perfect friend wingman should be someone who you are already friends with. Maybe it's someone towards the lower end of the food chain in your friend group, maybe it's a friend who has one two many beta qualities stopping him from being competition, etc.

Now you shouldn't ask him to be your wingman. Because you chose someone who will naturally elevate your SMV, if he knows he's a wingman several problems can arise. Firstly, he might behave differently, potentially hyping you up weirdly, as most guys don't have experience wingmaning. You don't want his behavior changed, you just want him there with you. For the most part, nobody wants to be a wingman, especially not often. This way, if everyone's out having fun, there's no reason this arrangement can't last as long as you want it to.