I say existing strategy because I am unsure myself what strategy the Germans had used that warranted such a heavy reliance on petroleum in powering the German war machine. However, I would like to know why Germany did not opt for an alternate strategy despite knowing of their lack of oil supply in sustaining their arms and equipment.
I'm not sure if why is the right question to ask here. Simply put modern warfare requires petroleum and lots of it. Without oil you can't fly planes, drive tanks, logistical trucks etc. Now the Germans weren't blind to this problem.
Early on before the outbreak of hostilities the Germans were already stockpiling oil that they were importing mainly from Romania and partly from the USSR. More interestingly Germany was also a leader in the production of synthetic oil. This is the process of changing coal (a resource abundant in Germany) into liquid oil. This focus on synthetic oil was based on the lessons Germany had learned during World War one where an allied blockade made it impossible for crude oil (among other supplies) to get into Germany in relevant numbers. Germany didn't have the access to the vast oil fields Britain and France ruled over in the Middle East and Africa so this focus on Synthetic oil was a large part of German industrial strategy.
Now the production of synthetic oil is more expensive and less efficient than pumping up crude. Germany did of course see that it would be impossible to keep up with Allied and Soviet production. This is why militarily they placed high importance in capturing oilfields and destroying/cutting off enemy oilfields while at the same time trying to protect the Romanian oilfields near Ploiești. Germany simply couldn't afford to wage a war of attrition against the allied forces. They famously tried capturing the oil fields near Baku in the caucasus during Operation Fall Blau, tried supporting locals to revolt against the British to threaten the large oil deposits in Iraq, had aspirations of a large pincer movement where troops from Egypt would enter the Levant from one side while troops from Baku would push from the other side. The Allies in turn intervened in Iran and occupied the country to make sure oil would flow to the USSR and wouldn't land in German hands, and bombed the aforementioned oil fields in Romania climaxing in Operation Tidal Wave.
All in all the Germans did try to adapt to their disadvantage situation and they definitely took it into account when planning military movements but a modern military (even one in WW2) simply relies on resources like oil.