The way they said it, I felt it was implied that it does not work anywhere near it's XI equivalent, but is actually the real deal aiding the player in their job.

As in, if it was, for example, Merlwyb, then it meant that the Admiral would leave La Noscea to join the adventurer in whatever task was at hand, not some simulacrum or magical construct. But it was NOT said directly, one way or another.

And even if it was the case, there's no reason to believe it's not something that can change.