And then what is the real difference between a Ross using shapers he trusted and a JN using shapers he trusted? That JN didn't want the risk of starting a construction company when so many qualified people were already out there? Seems like the same thing to me.
There is also the advantage that the shapers in a big construction company can also be very good and allowing them some freedom helps the gca vary his style somewhat. I can recall seeing features from other gca's that look similar to stuff I put in, and crediting that to the knowledge transfer of shapers from one job/archie to the other.
For that matter, I recall sharing some pix with a big name gca for an ASGCA project and seeing "my green" show up on one of their courses a bit later. So, steal from shapers, steal from archies, what's the big diff? Assuming no one steals the BAD ideas from others, maybe architecture got better faster than it would with everyone sticking to their own people, so its two sides of the coin.
Lastly, even within a firm that uses its own crew, there are changeovers in personell. TD or Pete Dye had to train new people constantly (or from time to time) because of natural turnover. It would follow that the quality of the course is partly dependent on how good a trainer they are, as opposed to how good a designer they are. I doubt the big boys get too many new personell when they hire Wadsworth, or whoever, to build a job. Heck, I rarely seemed to get new guys from the big contractors and when I did, every once in a while they turned out to be real gems.
Short version - I have never been convinced that the contractural relationship of the archie to the shaper is as important as the personal relationship. As Mike notes, if the only relationship between the two is a 24 x 36 plan, then yes, the shaper has to build something and will build what it is he thinks the plan says, always trying to improve it with his own touches.
But, I have rarely seen shapers move bunkers, etc. so it really is the finishing touches that show the shapers skill and presumably, the basic design concept is the archies. Of course, the devil is always in the detail, so I am not discounting those "touches" in the difference between a green, a good green and a great green.