Thats what I call preperations, when you do excatly that, to make your "universe" having an inventory of characters and walker-on's. But there is always an item that needs to made extra, and to remember that you have to ceep up with your time table, the extras should be within the time budget.

To do just a different camera angle and having the same characters/walker-on's, that is something you can only do a few times spread randomly over all the images. Or else it will be to obvious that the artist took a short cut. Here's the questions about what you will comprimise with:

Use the time to make the scene set properly and use global illumination, which to my taste make splendid renders, and have slightly difference in the mood of the image, which I believe only artists themselfs can tell the difference about?

Or, make the scene set faster, using more time on the lighting to get the right mood?

Who is the receiver, the artists or the regular man? The regular man: Hmm, has the artist used raytracer or global illumination?