Ah just let it go. The game is fiction and while it's obvious that they didn't craft their world modelling real life military and customs, the alliance is pretty much a distant backdrop in the game anyways. Yes, Shepard and Anderson happens to be part of it, and yes, it sets the scene for Mass Effect 3 in the defense of Earth, but for the most part, the game revolves more on the characters, the adventure, the reapers, and less so on little strict military customs. It's probably clear that the props were made by civilians, but really, when we are talking about a sci-fi fantasy here, where we have blue supermodels at the top of the universe, and giant head butting frogs that speak English, I don't think most people would really care which hand they salute with, how high their beret is from their head, how many threads are sticking from their uniform, how straight their collars are, etc etc. One has to really be deep in the forces to really care about something so trivial, but even then, it's just a piece of entertainment that is meant for you to let loose and enjoy. If we start criticizing every NPC like an inspection, I think we're taking things a little too seriously