Counterfactual: death of Hitler (of whatever causes) in 1941, peace initiative of new Führer (whoever), German withdrawal from Russia Proper, Nazi direct+indirect control of swaths of former Soviet territories
Factual: death of Ogodei in 1241, Mongol withdrawal from Central Europe, Horde's direct+indirect control of Pontic-Caspian steppe
What have been said (whbs): had Ogodei lived, Mongol forces would go all the way to the Atlantic coast
what would be said (wwbs): had Hitler lived, German forces would go all the way to the Urals, perhaps the Pacific coast
whbs: Mongol war machine unstoppable, given track record of previous campaigns
wwbs: German war machine unstoppable, given track record of previous campaigns
whbs: Mongol mobility matchless
wwbs: Blitzkrieg matchless
whbs: superiority of Mongol cavalry
wwbs: superiority of Panzers
whbs: generalship of Subotai, etc.
wwbs: generalship of Guderian, Manstein, etc.
whbs: European infighting
wwbs: Great Purge in USSR
whbs: European Knights' performance at Mohi and Legnica
wwbs: Red Army's performance in Winter War
whbs: Mongol forces can cope with European fortifications
wwbs: Wehrmacht can cope with Russian winter
Please keep on adding parallels.