Its always seemed weird to me that Germany always found Russia as the greater threat but then sent most of its troops to the western front to fulfill the Schlieffen plan. I understand that it was probably necessary for Germany to take out France eventually, but Ive always wondered why Germany didn't fight Russia first considering they knew at the time that it would only take Russia about 3 years to have railroads that could match Germany. It would take Russia much longer to mobilize than France, Which means the Germans getting hundreds of miles into Russia before they even have 400,000 troops to face them, and the capital could even be invaded by the Baltic, which was essentially a german lake at the time. I feel like Germany may have had much more success in early 1914 if they had planned to Invade Russia at the outset rather than declare war on France, go through Belgium antagonizing and forcing Britain to fight (thereby adding another unnecessary enemy). It always seemed to me an overly convoluted way to win the war and I think besides the technological advancement outpacing the war-plans, was probably among the reason why Germany lost.
Of Course I could see the downside: Russia would require at least a million troops to occupy (as it did in 1917) that would better be served against France, however if Russia was defeated quickly before it could mobilize, it is possible that France would think twice about joining the war to stop Germany, or if they did would be under the imperitive to attack Germany where Germany would have the advantage. The war would be a stalemate and would cost France millions of troops and would probably end in some kind of truce, albeit Germany with more leverage than they did at the end in 1918. The British blockade would be ineffective, as grain could be shipped from the Ukraine and Russia (as it was in 1917 but the damage had already been done) not to mention oil. It just seems to me the much more obvious choice.
Then again I also have the benefit of hindsight. Still, even in sports doing the same plan twice or even three times rarely works out (unless you have some kind of new game changing tech such as the panzer and Blitzkreig in ww2)