Here are some examples of using the Distribution shader with the Strata and outcrops shader.
The first image does not use the Distribution shader at all.
The second image uses an altitude constraint for the lower part of the cliff wall.
The third image uses a coverage reduction. I changed the Coverage from default 1 to 0.5.
The last image uses fractal breakup. The coverage is kept at 0.5.
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All these can be used separately or in combination. I posted the .tgd file for an example to play around with.