In the end, the whole nickname discussion is superfluous. Even if we unanimously decided on Mads, that doesn't mean Jason or the team will adopt it.
Really, we're discussing pet names here more than nicknames. And if that's the case, who cares if everyone else uses the same one? If you call him any of the suggestions here, we know who you're talking about. If it helps make you a bigger fan of the player, just use your favorite.