If you lose your anchors you're done for. It may take a while for a conference to lose its juice (cf Big East) but you lose your anchors and you're a shell of what you once were even if you continue to exist.
If the PAC loses 3 or 4 of the Cali schools, they rest of the schools scramble.
If the B12 loses TX and OU, the rest scramble.
If the ACC loses FSU and UNC, the rest scramble.
If the B10 loses the Michigan, Ohio State, Penn State combo, the rest scramble.
If the SEC loses Florida, Bama, Georgia, and LSU the rest scramble.
You have to keep your anchors in place. Just my opinion though.