Getting wildly off topic here, but I knew a TT rider year ago who was obsessed with his adjustments. When it comes to excusing a poor performance some riders will blame their gear selection, the course not suiting them or maybe the weather. However in Phil's case it was always the setup. The funny thing was I could never figure out how he thought the adjustments changed from one trial to the next, but at every trial when everybody else was warming up he would be fiddling with his saddle, stem and bars. At the end of every trial he would exuse his middle order time with statements like, "the saddle was too high, my hips wear aching by the five mile mark" or "the bars were too low, I just couldn't get into a proper crouch without giving myself back ache".
Kind of like MTB riders with their tyres.
Now I'm note saying Phil was lying, just that he probably wouldn't have had these problems if he'd found a good setup and stuck with it rather than fiddling with it all the time. The riders who keep tweaking their setup to account for things like a thicker pad in their shorts are probably just creating problems for themselves.
You should also consider that a lot of static bike setups work on rules of thumb, such as the arms should be at 90 degrees to the torso. These are good starting points, but they are not necessarilly right for everybody.
The last thing I will say about bike setup sessions comes from speaking to a rather successful time trialler last year. He was telling another rider he had wasted his money on a static bike setup session because it hadn't been in a wind tunnel. Partly he said because the "right" position isn't just the one that works best for your body, but also the one which is most aerodynamic. And also because at speed you need to take into account not only the way your body sits on the bike, but the affect the wind has on your body.
I suspect that a certain amount of this may have been down to psychology, but there probably is something in it. What is the most comfortable on a static bike probably isn't so good over cobbles at 30mph.