I've seen a bunch of discussions on things like this, and people pretty much always have decided that the fullborn would win against people from other magic systems. I do agree that the power of a fullborn are ridiculously overpowered with compounding, but against a herald, the balance could change, as the heralds can be reborn. The reason that this wasn't used in their battles was that they had to stay on Braize to prevent the desolation, while in a fight like this, we could say that they would immediately decide to come back. With this distinction, the fullborn would not be able to kill the herald, while someone at the 10th heightening could create a nightblood2.0 that would be able to kill the herald (although it will feed on their breaths during the usage).
Since Nale is the only herald who currently has access to surgebinding, I'd say that he's the herald to put in this fight--of course assuming that he has legal permission. I'd also assume, that for the sake of the fight, the three contestants should be aware of each others abilities.
So, who would win: Fullborn(with access to all 16 metals and a coin pouch), Nale(who can be reborn and is a 5th Ideal Skybreaker, with access to a pouch or two of stormlight-infused spheres), or Awakener(who is at the 10th heightening and has assorting things with him to awaken)