The point is, do you really think that doing a cable chest isolation movement is going to do more for your chest than a 350 lb bench press? I think not. If you're doing 4 sets of 15 of those you are spinning your wheels my friend. Funny how you're talking about Bill Phillips programs, yet I bet your "chest day" is something like this:
Bench press 4 x 10
Incline bench 3 x 10
Cable Crossovers 4 x 15
Or probably even more, that looks a helluva lot more like EAS, bodyforlife, bill phillips than what I do.
I've added 35 pounds of mass in about 8 months, drug free. I haven't TOUCHED a cable crossover or flye, and have never done more than 2 work sets for chest in a workout. Almost always one set (with rest pause).
Yes, some powerlifters do overtrain, that's very general what you said though. If you do 8 sets of deadlifts that are work sets, I don't care if you're ronnie coleman you'll overtrain on that. If you're talking about 6 warm up sets and 2 worksets, or up to a few 1RMs or something, then that's different entirely.
And everyone is not as different as you think.