The PSP Version of Persona 3 remedies the AI doing stupid things entirely by giving you full control over all allies. However, it also does stuff like remove some of the cutscenes, so for example, when someone walks into the scene it looks like they suddenly appear out of nowhere. I think it's more or less something you're supposed to play if you've already played FES or the PS2 version so you'd have an idea on what happens. The one thing I can say is
Spoiler Below When everyone's watching Nyx show up and Takaya crawls in, he's not shown doing so, and neither is everyone else celebrating Nyx's appearance so it's almost like they all followed you there or appeared out of nowhere, since all you see is Nyx showing up.
It's a rather nice improvement over a lot of other Megaten games, which really are showing their age with how you practically need a strategy guide to find your way through. (Good luck getting spell cards without either brute-forcing your way through or using a strategy guide)