Yeap. Absolutely.Exactly. He didn't listen to his Generals and took to war on multiple fronts. His troops in Russia were busy freezing to death getting nowhere and Stalin is still shitting out t34's from factories deep in Siberia, probably the best tank in the entire war.
He had assigned almost the 80% of the total German army to the eastern front... and he lost almost that entire number in that front also. Bad call.
If he had left that 80% of his army defending or taking more positions on the western front it is almost certain that the results would have been different, especially because Stalin was not a threat to Germany....
Old picture of Tic-Tac-Toe game played between Hitler and Stalin - 1941