I think you are taking the "dark twin" phrase too far. There were plenty of differences between Tesla and Edison, Musk and Bezos, mentioned as examples in the article. The concept of nemesis isn't built upon conscious beliefs, but "repressed attraction" as the article states. There's nothing fundamental about this concept that requires that you be similar in every way to the nemesis. A few similarities in the right areas can be enough to drive the repressed attraction.