Why not?
When you fill the buffer in one camera, you can grab the next. The secret is to match the cameras with proper lenses. For instance, you put a 600 or 800mm lens on D800, 400mm on D600, 200mm on T4i and as the bird flies by you, you activate the last combo with a 50mm lens. With a good shoulder harness and a little bit of practice, you can easily rotate between 3-4 cameras and harvest 5,000 shots in a few hours.