I've seen my dad after he got pancaked between a tree and an atv. It really didn't look any different from what you see online. Obviously it was more emotional due to WHO it was for me, but looking back on it, it wasn't what i saw that alarmed me, but who it was of. People act as if "oh if you don't react sickened then there is something wrong with you" Well, OR you are just weak stomached and don't want to admit it, so you have to say a person not affected in that way has a screw loose. Seeing a random person, especially someone that murdered raped and stole, get killed isn't something that disturbing that it should make you flip out like he does.
Not to mention, generally, strategists don't take part in fighting either in many cases, so why does him not liking to see a beheading make him not able to properly lead? The two are not connected. You can make rational choices despite not having the stomach for war. They are not mutually exclusive. Furthermore, do you know how you get over not having a stomach for war? You go to fucking war. The entire idea of him not being allowed to go because it made him sick is contrary to what the goal is. If you want him used to war, he has to fucking SEE war.