“Yeah, yeah, I know. Just stay out of our way. And I would appreciate it if you would refer to me as Mr. Fortunato.” “That means a lot to you, does it, Leon?” “Don’t push me, Steele.” As they entered the terminal, Rayford said, “As I am the only one who can fly that plane, I would appreciate it if you would call me Captain Steele.”
So, I assume Leon is here to be the muscle miniboss -- someone the heroes can beat without having eliminated the main antagonist.