Those guides are great rules of thumb from great players; but at the risk of making this sound more like real-life than it is, I find that feel makes a big difference. There are a hundred factors that go into the shots and technically that should equal a formula, but either due to VEM or some other factor, it seems to me that feel plays a big role in my shot analysis. For example, when approaching the greens at Kiawah Island, I know that some holes (like #15 and 16) play long, so I put a bit more on the approaches. Others, like #10 or #14, require just a touch less than normal. There's no magic formula for getting it close.
I know that wasn't about chipping and pitching, but I find the same thing applies there - if I think it's going to run, it probably will. If I think it's going to stick because of a flop shot, try the shot accordingly. Wind, lie, angle, lie around the green, elevation, spin, there are so many variables, so sometimes just looking at the shot and "feeling it" makes for the best shots.