As far as Clemson I have to disagree, Clemson was a brand name. 1980's they were a top program under Danny Ford, they won a national title.
1981 Clemson 12–0 (National Champions)
1982 Clemson 9–1–1
1983 Clemson 9–1–1
1984 Clemson 7–4
1985 Clemson 6–6
1986 Clemson 8–2–2
1987 Clemson 10–2
1988 Clemson 10–2
1989 Clemson 10–2
Their pedigree was no different than UGA, LSU, Auburn. Remember UGA went 17 years after Herschel Walker without a Top 10 finish before Richt went 13-1. Same with mighty Texas that went from 1983 to Mack Browns 4th year 2001. We knocked the only decent Texas team for 18 years from #3 to outside the top 10 with the 46-3 Cotton Bowl. LSU and Auburn are 2000's successful teams.
As far as Diaz......Every coach gets a pass year 1. Saban lost to ULM at Bama year 1. Stoops, Carroll, Tressell, Meyer, Saban all only won between 6-8 games.
This program based upon the weak division they play in, the simple fact that they play 9-10 teams every year that they out recruit by at least 10 spots on average(excluding this current year), should win 10+ games every year and the coastal at least 4 out of 5 years. Yes the occasional year when you get Clemson and a Good FSU as your cross-over games and the cycle is in a rebuild you might go 10-2 and not win the coastal. But you should also have the reverse, when the classes line up and you are senior heavy they should be 11-1 and challenging for a playoff spot and clemson for the ACC title.