My post apocalyptic team...
1. Olivier Queen aka Arrow
People who know dc comic superhero Arrow don't need explaining. For others, Arrow is a survivor. He survived on an island where there is nothing and by nothing i literally mean nothing.
This choice seriously doesn't need explaining. Still, i am choosing batman because, "he is Batman!".
This is not surprising at all. Who would you like to have on your side in post apocalyptic world other than king of hell? Crowley is a survivor and king of hell. I don't know anyone else better than him to be with me.