Interesting idea. I hadn't given it much thought. At the very least, I would assume each side was familiar with at least most of their opponents. Of course, they wouldn't be able to pick up on a secret identity or their public face. Take for example The Countess; she's a huge public figure, so she might hold back on confronting someone directly lest they recognize her. As I said in her profile, she's  not very keen on fighting, and she prefers to stick to her shadowy lair most of the time.