I think that Hitler should have destroyed the oil refineries in the caucus instead of trying to capture them.The loss would have hurt the Soviet war effort and would not have exposed the southern flank to a counter attack ( Uranus) . The British planned this to cut off Soviet oil to the Reich prior the attack on France. Destroying the oil would have saved the Reich uncounted losses and produced the same results as occupying them. Since the oil fields could not be brought back on line in time to affect the war.