In my opinion, it's an almost impossible theory to test unless you could wipe someone's mind, because you only get one first impression. If they watch all six movies in numerical order and hate it, you can't then show it to them IV-VI and then I-III and get the same kind of results with a clean slate. It just doesn't work. So if this girl liked the movies in numerical order as her introduction, there's no way to know whether or not she would have liked them better the other way around.