Ok, I am going to chime in here.
First, a high shoulder shot IS a CNS shot.
Second, if you don't hit CNS with something, then you will never get a reliable DRT animal. PERIOD. Even the "I shot it behind the shoulder and I got a DRT" shots, if you do a good necropsy, you will find that a piece of bullet or bone hit the CNS. All mammals are built such that they can take a good amount of abuse to their internal organs and still function for a while. You have to sever the connection between the brain and those organs in order to get a "lights out, right now" effect.
So, now that that is established, the amount of internal damage required to have an effect on the CNS with a traditional behind-the-shoulder shot requires either a bullet failure (i.e. multiple fragments) or a significant amount of shock (i.e. high frontal area at significant speeds). Both of those end up causing excessive damage to usable parts of the animal, and therefore should be avoided, in my opinion, not sought after.
