I am not a Psychologist, and since my Active service was during Peace time (Cold war under carter
) I am not highly informed about PTSD. That being said I must disagree with you (your source of info) some what.
As a young man my Dad painted,did 3 dimensional wood carvings, practiced taxidermy and many other things that required intense concentration and patience. At 18 he enlisted in the Marines, being assigned as a machine gunner. at the time the Marines were probably the most highly trained infantry the US had, especially when one considers that ALL infantry NCO's had served during WWII, those conducting training all had served in the Pacific in combat. He served a year in Korea, rising to machine gun section leader during the "outpost battles " of 52-53, awarded the Silver star and Purple heart he was meritoriously promoted to Sergeant. Returning home in 53 he again took up painting and his other activities,but less often, and with less patience which decreased as time went on until when I was very young he quit them altogether and buried him self in work. As I got older he had a lot of knowledge to pass on, but he was absolutely the WORST teacher I ever saw, He had NO patience left at all, any defect or short coming triggered instant rage. To make a long story shorter, at the age of 75 he has been diagnosed with PTSD. Based on my experiences with him it would seem that this is something that needs to be dealt with over a longer period and intense, realistic training (during maneuvers they used live artillery and mortars, one round fell short and killed several Marines) may help you to survive to HAVE PTSD but is by no means an answer to the problems caused by that type of stress .
On a bit of a tangent, he has also been diagnosed with onset Parkinson's disease, presumably because of the shock of close hits by mortars and artillery, the theory is that concussive shock has affects similar to the head punches that have messed up ALI. This may or may not be worth consideration by people who fire larger calibers in confined spaces, for example a shot gun in a small room.