Let me begin with a mea culpa including an editorial. As fans we sometimes use Schedule Strength as if it were a moral judgement instead of an analytical tool. We should not, for reasons I'll talk about in a bit. In the first entry for 2008 I made that mistake when I wrote
The "hall of shame" for 2008 includes five teams who have two FCS opponents.... and I was wrong to characterize those schedules that way, and about whether there's an excuse for such schedules.
... there's almost no excuse for three ACC teams to be on it.
First, although as fans we'd all like to see all of our non-conference opponents be top 25 teams. That's not just unreasonable, for all but a few teams it's combinatorially impossible. There aren't enough overlapping scheduling opportunities. See the distribution of conference games and try to match up only top 50 teams, remembering to not use week 15 for teams in conferences with championship games, and to leave each team three total "bye" weeks.
Second, it turns out the three ACC teams still have schedules that would probably rank in the top half of Division 1A. A useful measurement is something I call the "weighted median" which measures how top or bottom -heavy a schedule is. For the teams with two FCS opponents, the rank by weighted median is:
So, even with two non-FBS opponents, the three ACC teams still have schedules that rank in the top 50. It's true that not playing at least one more FBS team would improve the connectivity of the field, but that's only important to those of us who study computer ratings, and few Athletic Directors have us in mind when making schedules!