Many, many people. Yes. Although I was referring specifically to the Beginner's section since that is where it is most rampant. It occurs in most forums at different levels, some not very much, but most beginners are by far the worst. I would not say "most people"--nor did I say that. I said most people giving advice on this forum (Beginner's). But yes overthinking happens and it happens most often by people in your shoes with your level or lack of experience--Beginner's and BSL forums to be specific, although that does not prevent it from being in all the other forums. Some of the questions Thibaudeau fields are mindblowing.
We are not singling you out.
Not just newbs. Remember Defranco's program is geared for competitive athletes most of all. That's the population he wrote the program for. It works fantastically with other populations as well, but the training considerations are for athletes.
Athletes have 5-7 field practices a week. Every day, sometimes twice a day, and then games on top of that. The lower body takes an absolute pounding when you are running suicides or doing tackling drills, blocking drills, scrimmages, or running 400m in track practice every day. Or wrestling. The upper body does not take near the strain that the lower body does in contact sports unless it's wrestling.
Newbs can recover from 2 leg workouts a week. Newbs running sprints in team practice 5 days a week, plus tackling/blocking/wrestling/hitting....not so much.