Here is a pyramid that is not stepped per say but that is constructed of blocks that at one point had a "smooth" surface.
Here is a "stepped" pyramid.
These details of the first type, as in
The Great Pyramids at Giza constructed of blocks, shows that there is quite a bit of variation in the size and shape of the stones.
And in this image here you can really see the variation in the stones on the stepped type.
So really it is a matter of what you want to use this for and what detail you want to show.