Well, what about nonanimated tiles that still have smooth scrolling and movement?

Also, an idea for behind stuff, for all the tiles you can see at once you have an integer, that stores how far forward the tile is, where it's at the front and 2 high it would have 1, but back 1 on first level is 2, since its on the second row.

Make any sense? It'd be easier with a pen and paper.