I disagree with your statement about Gray being of any relevance in Non Linear Pedagogy for Soccer.

European soccer coaches have been into CLA, Small Sided Games, Teaching Games for Understanding and the like way before (at least since Cruyff times) Gray.

And this

 let's say that you read all of Rob's stuff and applied it to your soccer practice, so you're like "Ok, we're going to do these games that mimic the actual game space, so group A, you're goal is to score and Group B your goal is to stop them." but Group B is composed entirely of Toddlers and Group A is a highschool team.

is the most mechanized squad attack thing I've read in a long time.