That's the trick: the czar (and not Sokolov) took the hypothesis that the Poles would fight on his side, alongside the Prussians, and that other Germans would not support Napoleon, leaving the 72.000 french alone.
And once again, in peace time, units in all countries are spread out on large areas, to facilitate logistic. Not concentrated on a single frontier, with no ennemy force in front.
Please read the book, I can not sum up a well documented book of 300 pages in 3 posts. Also Lieven would be profitable, with his vivid description of russian troops in full offensive on the Danube, counter-marching to north although no result was settled.