Wrong conception of it maybe, I bet many have it. It is not 100% disabling or makes one an unstable individual. Actually, quite opposite, when I hear a loud bang or boom instantly and I mean instantly it has my attention and I go into a fight mode, that can be to look for cover, look for a tactical advantage, or to just look to see what the hell it was Jonny, that's it. On nights I dream of the Corps, those are fond and I long to have those dreams.
PTSD does not mean old General Patton Slapping the shit out of a soldier in a field hospital, all I am saying
Thanks. The sort of defenses you describe with machine guns, flanking fire, "final protective lines" and the rest did develop as the war progressed. By late 1917 and early 1918 reverse slope defenses in depth were being rapidly adopted. These were designed to create huge fire pockets using strong points defended by masses of machine guns and with huge artillery barrages preplanned throughout the battle zones between the strong points.
Churchill's six volume World War I history, "The World Crisis", is a great read if you are into military history. Amazon Prime's Kindle Unlimited has the last five volumes available for 'free'. Volume I costs $9.99 for a Kindle version. as much as I like all of it, I've found the last volume, "The Unknown War", is most interesting. This is on the struggle in the east between Germany, Austria-Hungary and Russia. The spaces were far more open and the war there featured a lot more maneuver given the absence of a continuous front as in northern France.
But as for the original structure of the armies in 1914, this Wiki page on the Battle of Le Cateau (26 August, 1914) gives a representative Order of Battle: https://en.wikipedia.org/wiki/Battle_of_Le_Cateau In 1914 the French, British and Germans all had far more field artillery guns than machine guns. At Le Cateau they fielded two to three times as many cannon as machine guns.