There's an old thread about this on another forum I hang out on where Thornton discusses the difference between reaction drills (which create reflexive actions) and conditioning drills. He posited that you would want your reaction drills to look and feel like they would when you are playing against a resisting opponent. Perfecting them in real time against resistance would more likely transfer over to a real fight as opposed to perfecting them in the air (though you would do both.)
Pull-ups, c+j, front squats, etc. are conditioning drills. I suppose hitting a heavybag would also be a conditioning drill, but when you're playing against a training partner and they are hitting back (even just tapping back, so you'll learn to slip or parry or whatnot) would help more with reflecive actions.
I don't think he was saying not to do repetitive drills, just that you can do them in a creative/alive way (even shadowboxing) or a repetitive way (like hubud--and if my coach is reading this, I am really sorry we disagree on this one!) (Having said all this I fully intend to continue doing dead stick drills because they are fun.)
Any this whole thing seems to fit well into CF methodology in that you are not isolating specific techniques/variables...okay, maybe that's a stretch, but it came to mind.
I totally agree with you on repetition btw!! And this has been proven and is described over and over again in every book from On Combat to Gift of Fear, etc. etc.