I wouldn't use the November scenario because that is exactly what you should do. Give them some time to understand how to be a pro and how to practice. then you put them in when they are ready.
Bradford, Sam - Started immediately 7-9, 18-15, 19th Defense: Pretty good showing.
Flacco, Joe - Started immediately 11-5, 14-12, 2nd Defense: Defense led this team.
Manning, Peyton - Started immediately 3-13, 26-28, 29th defense: He took his lumps and survived mainly because he's Peyton Manning. Most would not have.
Roethlisberger, Ben - Starter in 3rd game of season 14-0, 17-11, 1st Defense: Didn't screw up but Defense carried this team.
Ryan, Matt - Started immediately 11-5, 16-11, 24th Defense: Matty Ice is an exception apparently but also remember; Michael Turner 1699yds, 17tds. That helps.
Sanchez, Mark - Started immediately 9-7, 12-20, 1st Defense: All Defense and historic rushing. 600+ carries.
Stafford, Matt - Started immediately 2-8, missed 6 games, 32nd Defense: Bad team and it got him hurt. Got hurt again last year. May not ever become a stud because of the injuries.