#3 Matt Jackson

Matt's brother Nick is about to go to war in what's being labeled a dream match this week against Fenix, in what will be Nick's first singles match, according to him, in nearly half a decade. It's possible that Matt could end up in the ring with the other Lucha Brother, Pentagon Jr, but it doesn't appear that AEW is going back in the direction of the Bucks vs. the Bros yet, so that is unlikely.
While Matt has zero singles wins (or matches) in AEW, he has certainly has an impressive win-loss record at 7 wins and 4 losses. Matt is also the brother, sort of like Matt Hardy, known less for his high flying antics (even though he can definitely do it with the best of them) and more for his ability to keep the pace together and sell a good wrestling match.
Matt would be a great underdog babyface to take on the Superstar World Champion Chris Jericho. While he's unlikely to actually win the match, it would be a pretty good way to build to an eventually Jericho/Omega rematch, where Jericho shows how much better he is than Kenny and The Elite by beating all of his pals. He already beat Kenny once, he's defeated Cody, and there's no reason Nick and Matt Jackson can't be added to that list. If you have to choose one, though, Matt's your man.