Yeah, I think I do remember that. So, they implemented a couple of different clues. Still, I'm curious about the enemy AI and if they were possibly tailored differently for that specific world / segment. Just another reason to saunter gaily through KH1 again~
I posted a video at the following link showing the Green Requiems spawning above the correct doors:
I didn't let them stick around for long, so I don't know for sure if the AI is different. But I remember that they do float around and heal enemies, and that's pretty much all that Green Requiems normally do. So the only special thing is that they spawn above the doors, and they wait until you are very close to the door before they spawn.