Its known that the game developers are working very closely with the filmmakers and their teams from the movies, including, I believe I read somewhere, Tim Burton and Jerry Bruckheimer. With that being said, I imagine its easier, with the hectic schedules many filmmakers have, and more cost effective to work on several movies created by the same team at a time. For example, you wouldn't want to meet with Burton about Nightmare Before Christmas at one point and then have to pull him from his schedule at yet another point to meet about Frankenweenie. So this why we may be seeing inclusions from the same filmmakers at a time: lots of Pixar, both Nightmare and Frankenweenie from Burton are involved, and both Pirates and Lone Ranger from Bruckheimer. Of course this is all just my speculation, but seems like a very logical approach in my opinion.