When looking at this year's schedules, Huntingdon has played 3 teams who are moving on to the 2nd round including a 2A and a 3A teams. Those teams include Wayne Co, Waverly, and Milan. All quality wins.
Greenback beat two teams who got past the opening round of the playoffs in Coalfield and Oliver Springs. The convincing manner in which they beat Coalfield makes that a quality win. And OS was their closest game of the year, with that EASILY being the most difficult team they've faced.
Cornersville faced only one team who is still in contention with that being Mt Pleasant. The jury is still out on just how good that team is. While Eagleville didn't win this weekend, they took Riverside down to the wire, so they had a decent team as well.
Just judging by opponent record and success so far this season, Huntingdon wins strength of schedule by a MILE. I would say Greenback is the next most difficult and Cornersville 3rd of the 3. But it's a close gap between those 2.