Jim;

You're absolutely right to make the point: "torque measurement is supposed to be a measure of the distortion (stretching, advancement of the threads) of the bolt, not the resistance to turning the bolt resulting from friction.", but the fact is that there is a direct relationship between those two parameters, and this relationship has been carefully engineered by the factory, so that when they give you the torque spec, they are in fact indirectly giving you the "bolt distortion/stretching spec".

Where lubricants including AS come in is that they minimize sticktion (combination of sticking - a static parameter, and friction - a dynamic parameter) and allow you to approach the specified torque (plus K factor) more accurately on tightening...to say nothing of all of the benefits come dissassembly time!

Cheers