I don't really have any gripes about the initial choices being GM/plot dependent, so long as those choices are fairly permanent. After all, it's not like they room randomly every day (unless today is a strange/special circumstance?). I'm assuming they'd have their own rooms/dorms where they actually keep their own belongings, and whoever they're with is who they've been with for a long while now. That just seems like the most reasonable thing for a place I can only assume is run more like a school than a training camp.

My final contribution on Chinami's end is that, despite getting along with her, she's probably not rooming with Wilhelmina purely for continuity reasons, since the two of us (the players) decided they met in the library more by happenstance than anything.