Sadly, actual small unit combat training was a quite novel idea in WW1.
The fragmentation of infantry combat into platoon or squad actions caused by the need to exploit micro terrain features (or the need for night actions) for survivability was not adequately foreseen. Pre-1914 literature is concerned with battalion-level tactics mostly.
They did actually understand the problems caused by firepower and some authors did understand the necessary individual movement techniques, but they simply did not understand that command and tactics would break down into parallel small unit actions.

Ironically, the otherwise relatively conservative cavalry was often leading in small unit tactics (especially raiding and scouting) because it was anticipated that cavalry in action would often be about small units.


Few select units, typically meant to spearhead offensives, received much small unit combat training in form of simulated assaults on dummy trenches and the like.
Leaders of line units on battalion level and below had to improvise training based on what they've seen happening in combat (which required to survive the same yourself in the first place).
NCOs were in many armies the ones who shouted commands so the officers would not need to do so and might even be absent from the most routine exercises.