What Weapon Had the Largest Impact on the Outcome of WWII?

[1979]

They did, but that would have gutted transport production, they were not getting lend lease studabakers after all.

Considering the lack of standardization of german motor transport ( to many different types of trucks of different origin requiring different sets of spare parts ) I would say that, the transport situation was allready gutted, even without building 45.000 complex primemovers and APC's.

There were never enogh Sd.Kfz.7 to tow all of LW 88's, most of them went to the army as primemovers for the corps guns and divisional schwere Feldhaubitze .
Because the heavy AAA was emploied mainly in defense of static targets (cities, bridges, refineries ) that was not much of a issue , but if you use them in AT role, it would be.
( all of with a questionable advange over the PAK-40 which had 1,4 tonnes .)

If there is no bomber offensive then the Luftwaffe remains an umbrella over the German Army.
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Since the germans had allready lost the initiative by 1943, that would only prolong the agony.

Fighters can't force an enemy to fight, the bombers forced the Luftwaffe to fly and try to defend the Reich.

And they did so more or less succesfully, until the allies introduced a fighter with suficient range and performance to take the fight to the enemy.