Sounds too me that you might be in the 500-1000 range as far as decoys is concerned when you set up with your buddy. Depending on his e-caller and # of speakers, I'd add another e-caller first or perhaps more decoys as well. If you are happy with the sound and current #'s in your spread, than yes, I'd start to add some sort of movement to your spread. In my experience, I've had hunts that I believe the motion of vortex's, flappers, etc have helped seal the deal on them coming in but also hunts that they haven't worked out well. That being said, it doesn't take much to put the arms or flappers down after a couple flocks don't finish. Read what the birds are doing, and adjust from there.