It's prolly used like other arcade games with multiple chips, one for music, other for SFX. That said, I don't see any AM2/AICA refferenced there (even taking into account the fact the roms are bytesplitted).
//Edit
Ack, messed the VF4 and VS3 sets a bit (renamed the dsflibs while not updating the _lib tags in minidsfs).
If you don't want to redownload the whole 28 MB archive just to fix that, here are just the minidsfs:
