Here's some history on other programs who have gone through some hard times.
Oklahoma: 1989-1999 (11 years) 4 coaches; 3 losing seasons; 2 .500 seasons; Bob Stoops first year 7-5
Alabama: 1997-2007 (11 years) 4 coaches; 4 losing seasons; 1 .500 seasons; Nick Saban first year 9-6
So Cal: 1990-2001 (12 years) 4 coaches; 2 losing seasons; 3 .500 seasons; Pete Carroll first year 6-6
Notre Dame: 1997-2010 (14 years); 4 coaches; 4 losing seasons; 2 .500 seasons; Brian Kelly first year 8-5
Michigan State: 1991-2010 ( 20 years) 5 coaches; 9 losing seasons (0-11 in 1994); 3 .500 seasons; Mark Dantonio first year 7-6
Nebraska: 2002-2014 (13 years) 4 coaches; 2 losing seasons; 0 .500 seasons, Mike Riley first year TBD
The only program on there that even resembles our struggles is USC from 1990-2001. Bama and OU were decimated by NCAA probation and sanctions in those years. Notre Dame fell on hard times after Holtz because the school chose not to lower their academic standards like they did under Holtz. Michigan State was never where we were.
USC is similar though especially when you consider why they went through so many coaches in that time frame. It was because of some of their alumni much like ours who were accustomed to playing for NCs. Pete Carroll really wasn't a bullseye hire either. He was more or less comparable to Clownahan. Plus, he's the reason USC endured NCAA probation and sanctions. It remains to be seen, but I highly doubt they are a top program anytime soon again.