my (repeated) scenario is earlier control (if not annexation) of Austria, they tripled oil production domestically in all of Germany, IF they have concerted efforts in Vienna Basin AND found Matzen field, THAT is the likeliest POD, also because the infrastructure is there already, they are just adding more oil wells.
there is also obvious option of not settling for half of Romanian production? if they wanted to seize oilfields Ploesti is a lot closer than Baku. they could strike a deal with USSR, Hungary, and Bulgaria for division of the country?