There are several “before and after the war” photos from units in WWI. Some of them are beyond shocking. The pig headed generals just keep doing the same failed style over and over and over....
Here’s just one...
They didn't have much choice until the tank showed up in 1917/1918.
The main problem? No radios. Soldiers could advance with heavy casualties as long as artillery could support them. But field telephone lines were quickly cut by artillery and after a brief period of advance, infantry were without artillery support.
If the Germans had prepared two railroad deployments instead of West only and sat behind their fortified borders, they could have quickly defeated Russia and probably reached a negotiated settlement. In the East there was room to maneuver, the Prussian/German forte.
My wife's great-grandfather (a Pole from the area incorporated into Germany) volunteered for the German Army after Germany promised Poland independence. He was KIA fighting the Russians outside Warsaw. My wife's grandfather fought in 1939 including Lowicz, where the Poles fought for more than a week to control the approaches to Warsaw. He was a POW, almost shot because he possessed a German made pair of binoculars, but since he spoke fluent German and had the receipt, he talked his way out of it.
My great-grandfather joined the French Army in 1896 and survived all four years of WWI, with a year "off" in 1917 chasing insurgents in the Rif mountains. Mentioned in dispatches in October 1918 for leading an engineering unit throwing a pontoon bridge up under heavy fire over a river to pursue the fleeing Germans. His eldest son was blinded in one eye but still recalled duty in 1939 along with him and my grandfather, a recent widower with three small children, my father being the youngest. My father's older brother and another older uncle were drafted to fight in the Algerian War about a year after they arrived in the US.