The European edition of this album had these composer/arranger credits in the notes of its child album page:
Spoiler:
Tracks 1, 2 composed and arranged by Yoko Shimomura
Tracks 3 to 5, 7, 10, 12, 13, 15 composed and arranged by ACE+ (TOMOri Kudo, CHiCO, Kenji Hiramatsu)
Tracks 6, 8, 9, 11, 14, 16, 20 composed and arranged by Manami Kyota
Tracks 17, 19 composed and arranged by ACE (TOMOri Kudo, CHiCO)
Track 18 composed and arranged by Kenji Hiramatsu
I've removed them for now since I'm not sure what the source of these are. I was under the impression that Yoko Shimomura didn't come back to work on the remastered OST for Definitive Edition (EDIT: Apparently she was involved), and ACE+ isn't credited as a unit anymore. Actually, the game's credits specifically mention that ACE and Kenji Hiramatsu are "ex ACE+", so I would be very surprised if they were credited as ACE+ for the tracks on this CD.
Also, although this is from a user-submitted database, when I imported the Australian version of the sound selection CD, iTunes automatically found these composer credits:
Again, this is from a user-submitted database so I doubt it's correct. It did come in Japanese, however (I changed all the composer names to English/Romaji for my own purposes).
I don't know if there are any specific arranger credits for this CD, but I've added all the composers for all the remixed tracks to the composers field of this page since those are pretty easy to identify.
I haven't found any reliable source for arranger credits yet, but if someone knows anything please post it below, I'd like to know if there's a reliable source for arranger credits yet.