I don't know if you're a war gamer, but I'd really suggest trying out the game "1914: Twilight in the East". It is the single best modeling of WW1 I've ever come across for 1914 and by far the best on the Eastern Front I've seen. Super tedious and tough to play, but if you want accuracy you're coming to get mind-numbing complexity. In that came the issue of logistics and WW1 combat basically turn the entire Eastern Front into a giant shoving match, especially when you consider that radios mostly did not exist outside of the army-army group level; communications were one of the biggest problems, especially invading enemy territory, because you lose contact with advancing units, while the enemy has land line telephones to communicate with. Getting WW2 style quick victory offensives is impossible and even with a mass advance of multiple armies you end up with a nightmare of logistics, open flanks, communication breakdown, and the reality that you can't really just steamroll an opponent except on open ground and with vast numerical superiority. The Russians tried to 'steam roll' in East Prussia in August-September 1914, Central Poland in late Autumn 1914, and in the Carpathians in winter 1914-15. They all failed miserably and it turns out a much more flexible army using interior highly developed rail lines and good intel will just hit you on your weak flanks and kill you when your own communications were a mess. More than just about anything it was the inability for the Russian 2nd Army HQ to stay in touch with it's corps that resulted in the disaster of Tannenberg. In the Carpathians weather and terrain added the defenders in holding the line, resulting in around 1 million Russian casualties. So the Russian steamroller was basically a myth in the again of rail roads and land lines, because the defender could redeploy by rail and stay in communication via land line, while the advancing Russians had to rely on foot and horse and lacked radio to stay in mobile communication. You can point your steamroller in one direction and ride it to oblivion, because turning it isn't an option.