I think the idea of the party being represented by a single avatar is a fine thing. It helps prevent the problems of path finding, allies getting in the way, clutterdness, etc. Of course, it only works in a certain kind of game, turn based being a good example.
The other thing with the Final Fantasy series and similar games is that you often end up with up to nine party members (of which three are active). Could you imagine what it would look like with that many people walking around manga style?
Beyond Divinity is full realtime with little border between RPing and combat, so a single avatar wouldn't suit it.