Posted by JNG:
GR was outlining early ideas about why the engines were the way they were to Matt Jefferies even as the original Enterprise was being finalized. They weren't made up for Franz Joseph Schnaubelt or anyone else in particular-just a burst of creativity.
I wish this conspiracy theory would die.
Problem is, if GR was that intent on those rules at that point, it stretches credibility to believe he'd have signed off on 3 different ship designs that all violated them to one degree or other.
Either way, I think it's still safe to assume that these rules never gained that much importance in the grand scheme of things Treknological.