I think that more tanks would have been better than a standard 75mm gun. While both fuel and crews might have been a problem production would not have been, Allied atempts at hindering direct production failed every time.

Laying aside the fuel issue the type of these tanks that we are assuming the Germans were making would be important. If they were PzKw IIIs or IVs, I could be persuaded to say that not much would hve changed, had they been PzKw V or VIs then a prolonged war or perhaps a diffrent out come depending on the date of introduction.