The thing is, Hulk disc 2 is actually a genuine "Xbox Original Game Disc" - which appears as a DVD Movie to anything but an Xbox DVD drive (try any original disc - it looks like a DVD movie to a PC DVD Drive, with 11MB of video files, and no game information). So the disc format is almost like 2 separate, unique sessions, one side being the movie, the other being the game (which regular drives cannot see).
We can't recreate this format.... M$ has basically corrupted a standard format agreed upon by the DVD drive manufacturers to create their own version.
Simply combining the movie and game stuff in "one session" is simple enough, but the Xbox dashboard will probably choose the movie over the game material, as will most dashboards (I forget how I handle this in MXM - probably default.xbe is found first, but I'm not sure - turn off autoload and you could get it to work as you like).