if you look at the bottom half, of
this lofty mountain map, it has the "Mt Tamarrach" layout, with large vertical walls. You will note that chunks of rocks here are aligned in one direction (vertical), and the base of each "spike" could be going further down "behind" the "lower" spikes.
E.g. imho, working from
gives it more a "cliff" look.
random directions is fine because it does not matter where you put these cracks
That's true for random pile of rocks that had cracks from random reasons.
If instead you want to render a cliff -- a large part of rock that for some reason had been extruded from the ground by some geological process -- then the rocks are initially part of the same strata, cristals are laid out along one major direction, and the eroding force (wind, sand, water, mana ...) is likely to blow along one major direction, exploiting inherent weakness of the cristals to fracture the structures, hence lower diversity in the cracks orientation.
Now, of course, this only make sense if you aim for that type of terrain.
