Your logic is so faulty I don't even know where to start.
First of all, OU's O-line isn't playing USC's O-line. Comparing one to the other is nonsensical, because they won't come into contact. There's no matchup.
Secondly, they're playing USC's D-line, which is likewise the best in the country. It's silly to say that one will definitely handle the other. The fact is, because they're both so good, we just don't know. That's why they're playing the game.
Thirdly, USC doesn't have to have a O-line better than OU's O-line. All they have to do is have an O-line better than OU's D-line. Do they? It's hard to tell.
That's what Dama is saying. He's saying OU's O-line> USC's D-line and OU's D-line> USC's O-line. I only agree with half of it. Both defensive lines are better than the opponent's offensive line. Which is why I say it comes down to who outscores the opponent as being the one to win the game.