That is a way to do it, but usually rocks and boulders have very different characteristics from cliffs in terms of shape and details. When creating rocky environments you usually want to retain a consistency in detail level and shape size, even if they might be made from the same rock/mineral type. So if you take a human…
And to add to this thread myself, I really enjoyed this thorough breakdown by Jared Sobotta on some of the rocks/cliffs from The Last of Us: https://www.artstation.com/artwork/4965R1
Mesh size is pretty flexible, you don't need to worry much about detail consistency with world-space textures. In sort of an open-world context, most cliffs are multiple types of rock assets handplaced in areas where you want cliffs, with pebbles, grass, shrubs that are transformed and generated based on things like world…