The article that I posted didn't really look at any individual games -- just at entire seasons over a four year period and tried to make some observations based on that. Admittedly, it isn't exactly scientific, but it's the best 'body of work' analysis that I've seen so far. You spoke about the effect on players during the week of practice for the upcoming opponent after playing a HUNH team. True -- the article did not address that. It did, however, look at injury rates.
I remember reading in another thread some time back (I can find it if you need me to) about how to stop the HUNH (I think it was shortly after the Iron Bowl) and no one was talking about player safety, that I remember. A few people did mention exhaustion, but not as a safety concern -- more as a reason for a missed assignment.
I do remember after HS games -- especially ones where I would lose more than 5 pounds in a single game -- causing the next day or two to be recovery days. Luckily, we didn't practice until Monday. I believe most colleges just watch film on Sunday and Mondays they don't practice. or have very light practices.
I've seen a couple of suggestions in this thread that I thought were good. One being changing the way the clock runs in college to be closer to the way it runs int he NFL.
Something I haven't seen suggested was changing the TYPE of player to defend against a fast paced offense. A 330 pound DT is probably not the best candidate to play at a very face pace for an extended length of time (though that player is ideal to play against, say, Arkansas).
...or working on a different player substitution method -- like getting one player rotated out per play rather than trying to sub in a whole DL. With practice, I really think that defenses could rotate fresh legs in every few plays. Not wholesale changes -- but one, maybe two, guys per play. Again... just a thought.
Defenses will, eventually, not only learn to cope with HUNH, but stop it. They always find ways to stop the offense at some point.
The data folks are using in this argument don't take the fatigue factor from the game itself into account - it only measures the actual games. There is no accounting given for practices missed, slowness in recovery, etc. that can only be seen when teams are in practice mode week to week. Certainly, with it being football, fatigue is part of the necessary evils after a game. When fatigue issues begin significantly impacting preparation for the next opponent, it's going to be noticeable. And... a defensive coach like CNS is probably going to be adversely affected more than most because SO much of their defensive success comes from the mental preparation during the week.
If you played in HS, you remember some of this. I can remember the body fatigue for the first 48 hours after a hard-hitting game on Friday nights. However, what I can't remember is being so fatigued from Friday's game that I was still physically and mentally exhausted on Tuesday of the following week. That's happening more when you play in a "gassed mode"... and it is a safety issue to some degree.
Bottom line, though, is that you'll never get coaches subscribing to the HUNH to admit this. While I'm not saying coaches are totally unsympathetic to player health, at the end of the day success in their profession doesn't revolve around player safety. Rather, it revolves around the wins and losses... and if you're having success with this system, you don't want to admit flaws which may exist. BTW Hugh Freeze... telling folks that implementation of this rule may "cause some folks to loose their job" without acknowledging that many DC's HAVE lost their's due to the system YOU employ is more than just "a bit hypocritical."