Bruno came to notice something as the German, Austro-Hungarian, and Russian armies came together. Something subtle had shifted in the timeline, and it was not exactly all that surprising. To a certain degree, the same rules which applied in his past life still were applicable to this timeline despite its changes.
What did this mean? Well, at a very small level, slight changes in uniforms were made due to the nature of the shift in alliances. For example, in Bruno's past life, there were, for the most part, two different steel helmet designs that came to dominate the battlefield during the Great War.
If one were aligned with the Central Powers, then the odds were that they adopted the M1916 Stahlhelm, originally created by the German Reich, as their answer to head trauma caused by artillery shrapnel.
