You just don't get it do you. The elite schools in a conference can almost never be on top at the same time due to those programs always recruiting the same caliber of players, often from the same regions.
USC, Oregon, Stanford, Washington, UCLA would find it very hard to be on top at the same time because in order to do so you need the top players from the west coast, just isn't enough to go around.
Same goes for the south and the SEC, except you can also throw in Florida State, Miami, Clemson, Ohio State now with Urban, all recruiting from the same player base.