This is Trojan Football Analysis and the text from a Carroll talk at what seems to be a coach's clinic. (http://www.trojanfootballanalysis.com/wp/wordpress/?p=1066)
It is very long and interesting to listen to him discuss base philosophy which is where you draw the parallel to GERG. What was most useful was the types of players needed by position and how they rotate by base set. Is it exact? No, but I found it a good proxy for our team. I don't have a similar detailed talk from GERG to refer to. This is so long I split it into two diaries depending on topic.

Mod Edit: Again with copy/paste. I thought both of these were great links, but you (collective) can't just rip their whole article here. Anything not in quotes from here down was moderator, not OP'er.

"Before we go any further, let’s talk about personnel.  You want to get your best players on the field.  The open side Defensive End has to be one of your best football players.  Size does not matter as much.  We want an athletic player who can move around.

That's just on example, but they go through the entire defense in the article, but they do a quick specialization at the end about secondary play.

If you have a million reads for your secondary you are crazy.  They don’t need that even at our level.  All they need to know is their primary responsibility and then secondary.  At the highest level in the NFL the pass game is as complex as you can imagine.  However if a defender can play the post and the seam route then they can learn to play at that level. The thing that kills and breaks down a defense is a ball being thrown over the defender’s head for a touchdown.

There's more where that came from, and I highly promote checking that article out (link at top).