I'm pretty sure Eli Manning hasn't seen Cam play this year. Nor half of the league (offensive players). People assume NFL players keep up with the rest of the league. They only study film on their direct opponents.
Yes he has, because 1.) we played the Giants in preseason, and 2.) we played the Redskins, whom the Giants played, and therefore he watched film of their defense getting destroyed by Cam.
There's more than one team on game films, you know. When you combine common opponents and scheduled opponents films you have a chance to see almost everyone through the year.