Hmmmmmm, I don't think that is the explanation for the surface flow. It explains the basic phsysics of the flow of electrons, but not the type of flow and why it behaves in specific ways..
The logical explanations have been varied, but the flow of electricity basically starts out as a turbulent and chaotic flow, just as a liquid flows within a pipe. As time progresses and we add Milli seconds to the event, the chaos that tends to expand outward creates a laminar flow on the outside of the conductor, or in liquids, the pipe. laminar flow allows for a more efficient flow rate and less resistance. This is why multi-stranded conductors are less resistive, creating less heat than the solid variety.
This is the layman's explanation that we use in the field where we know that electricity, like a liquid, seeks the path of least Resistance on it's own. And no, we have not known this for a hundred years. And no, it is not that simple. we are constantly trying to improve wiring methods, and the field procedures we use to improve the process, just as they do in fluid mechanics by improving valve and piping designs.
Efficiency is the game, and with improved efficiency we lower costs and reduce weight. we are constantly learning, and nobody can tell me that we know all there is to know. Except maybe a engineer, because they tend to do that all the time.....:-)
There is constant friction between the field and the guys with the pencils...There is no formula, that I have ever been aware of that describes and can predict the efficiency of the flow, but over time we have made note of the better wire and cable designs as far as number of conductors on the bundle vs the conductor size required. wire engineers have this at their figertips, and I simply pick from the best quality based on practical experience.
I am the guy in the field who has to build the stuff the engineer conceives on paper...I usually do a pretty fair job of smoothing out the bumps between concept and reality, but it is not easy. Only 35 years ago, we had this all wrong, and were building electrical distribution systems that were faulty and could have been much better. We are constantly improving, and by no means do we understand it all.
That is why I responded to your claims. The mind set should be that we know that we don't know everything. Not that we do....Electricity is certainly no exception.