The only one that stumped me was FF3 - Last Battle! I wasn't familiar with the Pixel remaster remix but I would have eventually figured it out as the music continued. That was fun!
the one for 13 was completely unfamiliar and had no 13 vibes, then the one for Dirge of Cerberus sounded like 12. There could've been so many guitar-focused ones from 15 intended to trick us into thinking it was Crisis Core too.
Yeah, some songs from FF universe, especially guitar-focused songs can sound very unfamiliar and confusing. I have listened to (and played) only 6, 7, 7-crisis core, 8, 9 and 10. All the other FFs blend together for me.
UGH!!! I got DoC wrong xD Only played it once. Though 12 I only got because it felt Ivalice but I knew it wasn't Tactics, and MQ I got by process of elimination.