The one assumption that people often make is that the camera has to move. On the contrary, I’ve done many projects like this where the camera doesn’t move one bit.
One thing you can do is keep the camera stationary and move the objects. In the sample you show, there really isn’t much of an overlap in scenes, they each appear to move into place one at a time. so why have a huge comp for this? Move each one independently. Sometimes you might want to create a “master” null and parent everything to it, and just move the null.
If you must have that sense of space of moving from wayyy over here to wayyy over there, I’d suggest precomping each scene (or photo with layers, in this case). Then collapse transformations for each of the comps, and move the camera between the comps. This way, your main work comp only has a handful of layers, rather than ALL of the source layers.
Also, when moving a camera around like this, I always use a Camera / Null combo (parenting the camera to a 3D Null). It just makes life so much easier.
Harry J Frank
Freelance Motion Designer
graymachine.com