Some good points here for sure. I don't know why I've never read Lamb's book! A Lot of what I know about running an AR stems from Pat Rogers and Pat McNamara. They seem to have disparate takes on certain key elements of gun handling. My personal approach to running the AR platform is based largely on a hybrid (or bastardization) of those 'Pats' that seems most relevant to my life. I have always tried to implement my daughters rifle instruction with this system in mind.
I'm far from the most qualified instructor, but I'm what she's got. At least I buy her guns and ammunition.
Also, I'm certainly not a dogmatic Cooper person, but I think invoking Cooper's name is still probably the easiest way to express a certain ethos. P-F members are likely to pick up on the meaning quickly. I read the Art of the Rifle years ago, and it was pretty much a paradigm shift for my thinking at the time. Techniques and equipment may have evolved way past Cooper in the time since his death (or before it), but I don't think anybody has improved on his communication of the overarching ethos regarding the armed citizen and the rifle.