Yeah that is about the same but the objects in the scene can be baked into displacenment/normal map and cut down unnecessary polys for the renderer to go faster. I want to point that when renderer start to process, the entire scene is all 2D completely to the image for animation. Models with low polys is ok but not the same as renderer because LDNM cuts down the hidden polygons and also cut down unnecessary polys that displacement/normal map can cover. This can preserve the resolution of model shape, all the objects that show in screen is captured into displacement/normal map. That is why I call it Layers Displacement/Normal Map renderer.