of course the tactics employed by the military still harked back to the Napoleonic days when the slow march on the enemy positions had a psychological effect on them.

The problem is that the weapons were much better and deadlier. Soldiers were supposed to advance by walking slowly (not running, or dodging as would be the natural reaction) or crawling. Its not even a question of cowardice (that was for the generals, how many of those were in the waves of attack)

Its hard to imagine but some people (to avoid being drafted) would inject kerosene into their arms or legs so that gangrene would set in and it would have to amputated. I recommend reading the Good Soldier Schweik by Hasek who lived through that time.