If no dribbling occurs, shape maintenance becomes both a more important and in quite a lot of cases, more involved task. hence why dribbling is really valuable.
If the disc moves back and forth between the back two players, as long as neither are close to the side-line, no adjustment really needs to occur, although if the disc moves forward as part of the swing, everyone will need to shift downfield equally.
If the disc moves to the wing shape point, the shape needs to rotate sufficiently to maximise options, while preferably still attacking downfield. I.e the closer to the middle the wing shape is, the more rotation needs to occur, the closer the the wing point is to the side line, the less rotation occurs.
This is just to show you the difference if the disc had moved all the way to the side-line. From Here if the disc moves down the line to the back point, rotation must occur again.
Notice the thrower is moving into the back shape point, which is in-field but wasn't downfield from where they threw it.
obviously if it was a deeper throw, they'd have to run downfield.
If the disc moves back to the near-side back (7), if the near side back, is close enough to the middle of the field, no rotation needs to occur. BUT it's much more likely they will still be somewhat near the sideline, in which case everyone must rotate, back around. this gives the deep side-line shape point, some space to move, if we didn't rotate, they would be stuck on the sideline, and not a useful threat on the field.
winning.