No, he is not looking too much into it.
The way it was explained to me by a vet was this:
Red arrow: moves forward when YOU have possession.
Blue arrow: moves back when YOUR OPPONENT has possession.
Very simple.
so a DC/DMC playing in 3-1-4-2 with red arrow:
When opponent has possession:
------ST---ST-------
---------------------
-ML---MC--MC----MR-
--------DMC---------
----DC--DC--DC------
When you have possession:
------ST---ST-------
---------------------
-ML-MC-DMC-MC-MR-
---------------------
----DC--DC--DC------
I have also been told that it is not useless to put blue arrows on defenders and red arrows on strikers:
Blue arrows on DC - Apparently you can keep DCs from advancing and getting caught out, but they also wont go out to block the long shots.
Red arrows on ST - Apparently you can keep STs up in the box with a more attacking mentality.
I have been trying putting blue arrows on my left and right DC and leaving my middle DC with no arrows to test this. I consistently have the best GA in almost every season that there are no token buyers in my league.
Otherwise, it is useless to put red arrows on STs and blue arrows on DC.
ALSO, I heard that you put blue arrows on your defenders to keep them from running all the way up and accepting passes from your attackers. Most of the time, its a pass to an open player and its your DC who facking misses! I cant confirm this but I know there is a thread on this and someone knows for sure.