I really don't understand if Balkan delay and Rain affect the outcome of Soviet-German war , or at least a draw at the end of 1941. One more month only probably enabled German to destroyed two or three more Russian Armies ? German army were exhausted without getting a large quantity of supplies or manpower. Soviet still can frantically raise another ten Armies in Nov 1941. If German cleared up the remant of Western, Briansk and Reserve Fronts in Oct, she still needed to face ten fresh Armies from the East. The result is the same.
In Poland, German had an edge in manpower and military hardware. German had 1,513,000 men committed in invasion of Poland plus 50,000 Slovakian troop. Polish Army had 1 million men. in Every battle, German can depoly two or three time of force in annhilating Polish troop. In Radom, 8 German divisions against 3 Polish division, in Andrzejewo, 4 German against 1 Polish divisoin, in Kutno, 18 German divisions against 8 Polish divisions plus 3 Brigades. And German had air superiority , much larger tank force and stronger motorized troop.
In France, German superiority was not so obvious, German even had less manpower in front. But French had almost mobilize all troops and its industrial area and capital is closed to border which enabled German to win the war in initial period of war.
In Russia, they just wanted to repeat battle of France, so one blow will led to collapse of Russia. Given the size of USSR, manpower, resources, and above all, political stability. German leadership all assumption are based upon history record : 1917 Revolution brought the collapse of Russia after one by one military disaster. In house discontent also led to revolution. Finnish war of 1939-40 confirmed the weakness of Russian military after purge. But they igoned the same time Soviet victories in Nomonhan in Aug 1939. Guderian figure on large Soviet tank fleet, was ignored too. German only committed 3,050,000 men for war in Russia plus 550.000 allied troop for such huge territories. For France and Lower Countries, German had 2,760,000 men.
Complacency led to all these mistake.
They must know the vast territories of Russia, ableit the sharp increase of motorized troop in comparsion with 1940 campaign, it was not enough for that job. If not revolution happened in Russia, they will go on the war forever. the power of Luftwaffe was less in Russia than in France in 1940. Even German friendly policy toward Soviet minoities, I suspect if it work for collapse of Russia. Many authors always focused on this point is main factor for defeat of Russia.