I'm not sure I get your point. Are you saying that for them to be the same, Nightmare Star would have to appear before. In the cartoon? What is the point, since we're necessarily talking about fanon anyway?The comic mess this up but I don't care about them. Also, I don't see a reason to think of Nightmare Moon as a different entity when Luna has so much guilt about the stuff she's done as Nightmare Moon… Considering she actually had time to do anything as Nightmare Moon.But we've seen Celestia "fighting" and she didn't even wear armor in that timeline with the war against King Sombra.