I assume the premise of the thread, and your regarding your "stats," is the won/loss record is more of a factor based on our defense, and the fact that the opposing teams had an experenced QB playing against leading to our losses, versus inexperienced QB's leading to our wins.
There is one fallacy to your position in my opinion. From November through the end of the 2014 campaign, Georgia Tech's Defense ranked 14th among Power 5 teams in Total QBR (31.7), 21st in rushing yards allowed per game (138.8), fourth in interceptions (9) and 11th in points allowed per game (22.3). They're also returning 8 starters from that defense along with several experienced backups and, hopefully, getting back a key starter, Jabari Hunt-Days, to step in for Green, who is the graduate from the defensive line, so in essence, the defense could be returning 9 starters back.
This means that as the season progressed (after the Duke and North Carolina losses), the Yellow Jacket Defense improved DRAMATICALLY and shouldn't be lumped into the same bucket as the first portion of the season. I also suggest that because of the improvement, and the fact that they're returning starters and depth, we should anticipate more of the improved defense next Fall than the one the "struggled" against experienced QB's.