Ezekiel: Lasts 1 challenge, eliminated. No time to strategize or form bonds.
Eva: She COULD potentially be an antagonist but I think they'd used her physical power to intimidate others rather than tactically strategizing, although I some way making people fear you and listen to you can be considered a strategy, it's not Richard Hatch smart or whatever.
Noah: He also has some antagonist potential. Why not? In World Tour it hints that Noah can form bonds, leading to alliances and strategical tactics. I think he would be a great antagonist should it happen.
Justin: He had his moments in Action, faded away fast and turned into a comic relief character. It's like the creators changed his role when the series went on!
Katie & Sadie: Yeah, I don't need to explain why do I? No strategy plans or brains, too close to other people. They could be used in an alliance, but not their own tactics.
Tyler: It would not fit his personality. He tries to impress people, doing his own thing or talking with Lindsay. Not going to happen.
Izzy: Too crazy.
Cody: I don't see Cody as a strategist, more of a follower/background character.
Beth: Has a strict policy of being nice to people, no tactical idea of the game either.
Courtney: She did, in Action, somewhat.
Harold: He COULD but I doubt it would fit his persona.
Trent: Too easy-going, seems like one of the characters that doesn't care weither or not the wins the money.
GxB: Two-words: making out (constantly). If they stop it fits in the category of 'it won't fit/work with him/her'.
D.J: Action proved that he doesn't like being 'guilty' of pushing/back-stabbing others.
LeShawna: She did in Island and Action, however it always involves eliminating Heather and it's not because she's a threat (it's they're hate for each other).
Duncan: He did in Island, somewhat in Action. I personally thought the guy's alliance in both Island and Action should have lasted longer rather than dissapear of the face of the earth in the next episode. Same for the DuncanxHeather alliance, a week and it just...vanishes?
Gwen: Too negative, no charisma, no tactical idea of the game.
Owen: I'll stop here. You know why...