On why USUM was split into two versions:

>"This time around there are differences in the story between the two versions that lead us to a split. But one particularly appealing aspect for us in creating two different upper versions is that we can get many more different Pokemon and characters into the story and into the game itself. If you try and force all of that into a single upper version then the relationships between characters and their interactions they have can start to get a little bit confused and a bit disjointed, whereas if we separate them into two versions we can really focus in and make sure there’s a strong core to the story. Splitting into two versions allows us to draw the most from the characters in the game, and hopefully players will enjoy that."
- Pokemon Ultra Sun and Ultra Moon director Kazumasa Iwao

Is he right, /vp/? Did USUM have a strong story core that wouldn't be possible with just "stars" or "eclipse?"