The Germans outperformed per man or per unit of military capital, did not outperform the western allies overall, did outperform the Russians overall. Mostly because of doctrinal weaknesses in the latter case, and mostly because of smarter tactics and a professional officer corps.
They also had lousy strategic direction, were completely outplayed by the Russians in operational "big chess" terms, threw away their armor reserves recklessly in hopeless counterattacks, nailed their infantry positions to the ground and needlessly lost forces by doing so, etc, etc.
And no, the Nazis weren't better at it because they were more Sparta like or more tyrannical or cared less about human life. They lost. They performed well tactically in exactly the same manner the Germans of 1914 had, and the Germans of 1870, and the Germans of 1866. That's the result of a tradition that runs from Frederick through Gneisenau to Moltke the elder and von Schlieffen. Nazis didn't make it, they executed not a few of the men who actually did, and they thoroughly wrecked it, leaving ashes.
We need to remember the strategic disadvantage France had against Germany in 1914. The German economy was much larger than the French. The German population was 50% larger than France's. Germany very clearly had the advantage, and they pressed it, hard, with the Schlieffen Plan. The French were certainly pressed to their wits' end: the stories of reserve troops being ferried to the front in Paris taxicabs is not a legend.
But the French won the Battle of 1914, at the Marne.
Head to head, Germany on France, with Germany the more populous, more powerful country by far, in a direct duel in the field between Germany and France, France won and Germany lost.
Of course France did not have the industry or the manpower to be able to do it again and again and again: Germany was certain to win a war of attrition against France alone, because Germany was so much more powerful.
Nevertheless, if we focus in on comparative militaries, one on one, in a head to head duel, the French defeated the Germans at the Marne, and not the other way around.
This needs to be said, because it presents a truth that 1940 obscures. The most dangerous and powerful enemy of Germany was France. Not Britain. The British commanded the sea, but the war was decided on land. Not Russia. France. And the numerically and industrially inferior French put an army in the field that faced the vaunted German military machine virutally alone in 1914. And they beat it.
1940 and the catastrophic failure of France was the surprise event that opened the vistas for Hitler's madness.
The precipitous fall of France was a surprise, a surprise which opened up opportunities for Germany that unfolded into the nightmare of World War II.