You are mistating facts, once again. Kozak stated that were it not for the fact that Lenin signed the Brest-Litovsk treaty in 1917, the Germans likely would have been in Moscow. He never stated that the Germans actually were in Moscow.
No, you're not getting the reading comprehension. I stated, WW1, Germans in Moscow? Try that as a question of logistics. Trench warfare and lack of mobility. It took the Germans 3 years to take Poland, barely. The Austrians were on the run as were the Turks. So I hardly doubt, the Germans who were stretched to the breaking point (why the Kaiser gave 50 million deutch mark to Lenin to get Russia out of the war) would have gone very far, especially when at their best they still couldn't take Moscow in WW2 with mechanized warfare.