The weather that delayed the invasion the first day, and was still persistent the second day (the day they chose to go anyways)
Kept a German naval patrol in.
Imagine if that patrol went out, and was able to provide advance warning of the allied invasion
First: Your forum profile states that you're 22 years old. If you are actually younger than that, please say so.
I understand what you're saying about the weather, and your previous hypothetical re: orders that were never given that probably should have been, fully. You appear to have done your homework, pun intended; you seem to know the facts of the case re: the Normandy invasion. That's respectable, and I commend you for gaining an understanding of the facts before asking for more detailed info.
I assert that your error stems from a misunderstanding of the way "luck," responsibility, and especially, culpability, work in our culture. The argument that you are making, in favor of the Nazis, is an argument you can't win, not in this paper, because whether or not you realize it, the argument you're making strikes at the heart of how every first world nation assesses 1. culpability and 2. military competence. You're either suffering from an extreme misunderstanding of appropriate situations to which one might apply the phrase "bad luck," or you're arguing that no amount of preparation matters, command structure doesn't matter, unity of command doesn't matter, balance of risks doesn't matter, and that the Nazis got their asses kicked not because they goddamn
lost, not because German command failed time after time after time until the center could not hold and no matter the elan of the brave young Nazi troops, the Allies tripped over their own feet less, and when the Allied command failed, the men on the line were able to absorb those failures and keep moving.
Germany had infinity chances to not suffer defeat on the beaches of Normandy. The German people could have not allowed fascism to run riot over their fatherland and pretend everything was okay when their neighbors went missing. If there was one single German man alive who would stand up to a diminutive, shrieking, wannabe-painter with a bad haircut, and stop him from sending Germany's most promising youth to die on two fronts at once, then they could have avoided defeat. If they had made the right decision instead of the wrong one at many many junctures, they could have avoided defeat on the beaches of Normandy. If they had not engaged in a scorched-earth campaign across fucking goddamn brave little Belgium when they were starting WWI 30 years prior, they probably could have avoided defeat at Normandy. If they had treated Belgium with just an ounce of respect, if their Foreign Minister had not ADMITTED to sending the Zimmerman Telegram, if they weren't so German all the time then yeah, the largest armada ever assembled in human history wouldn't have landed on that beach and run, headlong, into machine gun fire, just to wreck their faces. If that's your definition of bad luck, then nothing means anything.
Your thesis is actually just nihilism.