It's not whether he's the best. It's whether or not he thinks he can win with the other two given all the other pieces around them. Having two scholarship players who do nothing other than ride the bench in order to play a Freshman isn't exactly the best way to build a team long term. Not having to start a good quarterback until he's had a year to learn a bunch of stuff about the college game is.
If play was elevated across the entire offensive side of the ball (or heck if just the offensive line played up to their potential), you could throw the ball 15 times a game and still win out against our schedule.