Many historians note that Operation Barbarossa was a big mistake. But I was talking to my history teacher yesterday and he said although we now see it as a mistake, the Germans had many opportunities to win. He briefly stated about the resounding early successes and far superior airforce. His main point though was stubborn nazi leadership who refused to allow withdrawal in certain battles- he said that even though this is a small thing l, it could have made a big difference in the end. When I told him that the Soviets also had strict no withdrawal policies ( not one step back order), he said it was different for the Russians as they had more manpower. Is he right and could it simply have been better Nazi leadership in small decisions like retreating to reorganise that could would have won Germany OB?
Discussions about Barbarossa tend to see a great deal of back and forth on the question of "was it a close run thing," including in the realm of academia. There's a lot to understand here, but the heart of the issue is an attempt to explore and reconcile to twin truths that
A) the German invasion of the USSR was appallingly planned, hopelessly unrealistic and crippled by insurmountable logistical shortcomings
and
B) That the invasion nonetheless dealt a staggering blow to the USSR, killing millions of Soviet soldiers and civilians, and ultimately placing nearly the entire USSR west of Moscow under Axis control, albeit shakily.
Your teacher, however, is wrong if they're suggesting that
"better Nazi leadership in small decisions like retreating to reorganise that could would have won Germany OB"
While they're certainly correct that German military leadership was rigid to a fault in their execution of many aspects of Barbarossa, there was no prospect at any point of the campaign where a strategic withdrawal and reorganisation effort by the Wehrmacht (beyond those which were, in reality, carried out) would have been either useful or feasible. The Germans did halt the offensive several times both regionally and across the entire front, including prior to the Kiev encirclement and prior to the drive on Moscow. Both cases saw sweeping reorganisation and redistribution of German forces, with all the additional logistical nightmares that might have entailed.
A German refusal to give up ground and consolidate was more important during the immediate aftermath of Operation Typhoon - but it's critical to understand that by this point (mid-October), the invasion had already conclusively failed. German forces were exhausted and stretched to the brink, and the Red Army maintained an enormous strategic reserve ready to commit against any further attempts on Moscow. For a number of reasons, the Wehrmacht was committed to a final series of assaults throughout October and November which were both fruitless, enormously destructive in lives and fighting strength, and then left the army perilously vulnerable to the counterattacks which followed through December 1941 - January 1942.
I've written in greater detail about the fundamental flaws which undermined Barbarossa from the start here. While there's without a doubt a great many aspects of the invasion bungled by the Germans (to say nothing of the Red Army, who I barely discuss here but which was plagued by crippling shortcomings), it is wrong to suggest that any number of small changes might possibly have altered the outcome of the invasion. Barbarossa was fundamentally flawed from the outset, and with hindsight we can say that at no point throughout the campaign were its prospects of success in question.
For further reading, I'd recommend David Glantz Stumbling Colossus for discussions of the readiness of the Red Army during the opening of the campaign. For a German perspective, I'd suggest David Stahel's Eastern front series, beginning with Operation Barbarossa and Germany's Defeat in the East.