USC had 43 scholarship players available at Oregon. Yes, 43. To say that those numbers don't matter because this is the Pac-12 is not a valid argument. Oregon runs teams down with their speed and wears out depth by their fast paced offense.
And by the way, what "15 starters" are you referring to? Below, I'm going to list 10 starters that are all FR/So, so... it's not possible to have 15 other starters. And, before you try to pick this apart, realize that a RS Sophomore has not been in the system for 3 years. They had been in the system for 2 years, and it was their third year in the system. Big difference.
Last year, USC's starters consisted of:
Freshman LOLB
Freshman MLB
Freshman ROLB
Sophomore CB
Freshman TE
Freshman LG
Sophomore RG
Sophomore RT
Sophomore WR
Freshman WR
That's a young team. Did they have more TALENT than a lot of Pac-12 teams? Probably... but they're so young that they were painfully short on experience.
To expect a team that has that kind of youth to run the table is illogical.
USC had 67 scholarship players as of Novemeber 30, 2011.
USC football: Scholarship count (11/30/11) - USC : The Orange County Register
A redshirt sophomore has been working out with the team and practicing with the team as much as a true junior. The two sophomore olinemen were redshirted. One of the biggest problems for offensive linemen is getting strong enough. Those guys had 3 offseasons in a world class strength program. Redshirt sophomore olinemen are quite common.
For you to even argue that a redshirt freshmen is the exact same as a true freshmen is laughable. Why can a redshirt sophomore enter the draft when a true sophomore cant if they are the same?
Matt Kalil, Khaled Holmes, John Martinez, Kevin Graf, Matt Barkely, Rhett Ellison, and Curtis Mcneil all had at least 3 summer workouts and summer camps with the team on offense. All those guys were on the starting lineup against Oregon.
Wes Horton, Christian Tupou, Dajohn Harris, Nick Perry, Jawanza Starling, Tj Mcdonald, and Isaih Wiley were the starters on defense.
I was number off, it was 14 upperclassmen starters. Kiffin got to redshirt 16 freshmen last year. He wasnt hurting too bad on depth if he got to that
The PAC 12 is offense oriented. Not to mention it was extremely weak last year. So yes, I do expect a team that easily out recruits every other team in the conference to run the ship.