I heard what you said, and I said it's actually kind of a strange view. If you were to go to Iraq, and see a bunch of dead soldiers lying on the ground, you probably would not say "Hmmm, the must have fell out of a transport plane. How clumsy." No, you'd probably say "OMG! What a terrible battle that must have taken place here!" Granted, you know it's Iraq and know ground battles took place there. What if you didn't know you were in Iraq? Would you still think they fell out of a plane? No, you'd assume they died from battle. The problem with your idea, is that it's overly complex, and not in line with the theme of the piece. You're assuming the creators had some comlex backstory unrelated behind the dead soldiers, completely unrelated to everything else that's going on with the piece. To be quite honest, that is an extremely strange viewpoint, but then again, us nerds aren't known for thinking normal. Most likely, the people who created it, who have degrees in this stuff and are always are thinking with themes, are not going to put something in their piece that has some complex backstory unrelated to the events happening in the piece. Most likely they were thinking along simple lines, and that is: humanity getting its butt kicked by ugly alien bad dudes, and everything you see is the aftermath of that conflict. Even the crashed Hades, which we all know doesn't belong there, those guys must have put in there to conceptually show some wreckage from the same battle we saw moments before. You see, it's all very simple, and very straightforward. The simplest answer is always the most likely one.