I'm always going to bat for large, stiff woofers with high excursion capabilities over small woofers no matter how many. The distortion specifications are pretty clear.
The good reasons for small woofers are usually more related to having limited bass not waking the room modes that are deeper. So much of what is attributed to using small speakers because they are faster ends up being caused by room mode issues, not speed.
As for soundstage, not sure but maybe it has more to do with wide baffle speakers?