I still have never seen a definitive 'This is what were doing' piece on our S&C to be critical of, but one part of it is a problem. Or at least it's at the core of what can be perceived as a problem.
You mention 'No reason they can't work on everything at the same time' and that's accurate to an extent, IF you're not asking a kid to gain huge amounts of weight in short order, naturally and without synthetic help. No two bodies respond identically to weight training and increased caloric intake, but one thing that is consistent is a hyper calorics state will lead to an increase in body mass. Some of it muscle, some of it fat. Ask a 19 year old kid to gain 40lbs in 2 1/2-3 years and while it's not a problem, you're still likely to see an increase in body fat, depending on the kid. Ask a 19 year old kid to gain 40lbs in an off season and a half, naturally, and you're going to see more added body fat. Is it enough to effect performance? Likely to a degree. Is it part of the flexibility issues we've seen with guys like Benhart? Maybe.
Benhart came into the program at a little less than 290. At 6'9". That's a pretty big kid. He's listed at 330 now after two years in the program. Is that too much weight? Not for a 6'9" frame, but thee 40lb weight gain is likely part of why he looks stiff. I didn't say 'stiffer' because I didn't see him play high school football and even if I had, he likely physically dominated his opponents to the point that any technical deficiencies would have been masked by his sheer size. Last year that wasn't the case. Too much weight on one foot or the other or half a step slow and he's having to recover....at 6'9" 330 against an equally large adult male. The result was he looked stiff or slow at times and got beat. A lot of that has been attributed to our S&C program. I don't know how much of that is actually accurate, but with Benhart, he's still learning to adjust to his new size and the kid across the line from him. Looks bad sometimes. If he was a fifth year senior who had gone backwards from an athleticism and performance standpoint, sure. I get it. Piper had a similar trajectory.
Jurgens is another matter. While I understood/understand the staff making the switch from TE to C, the weight gain that was required in such a short amount of time was likely overall detrimental to him physically. It couldn't have been more than about 75% lean body mass in a perfect world. Likely even less than that. So now you've got a kid, a strong, quick athlete at his coming in weight of 240, playing a new position against bigger, more physically mature kids who've been playing at their football/weight training enhanced weight for some time. Again, it looked bad and he carried bad weight in 2019. Looked leaner last fall and his play improved. Still gets lumped in with the S&C conversation and while I'll buy that in 2019, it wasn't his only problem and the only reason he didn't play like a seasoned center.
My point is we have a lot of moving pieces, headed by a losing record, that we're trying to lump into the S&C programs deficiencies and I'm not sure we're even close to accurate. At least some of my theory will be proven correct or incorrect this fall. If we stay static from a performance standpoint with another year at the training table, in the weight room and to mature on and off the field, we have issues beyond youth/inexperience. If we see a big jump in the right direction, isn't it possible if not probable that we've wrongly tagged 'getting beat' as a deficiency of the S&C program?
Just something to think about.