can anyone shed some light on how to control, for example, rocks and grass separately? I am trying to break the slope so its not so smooth, like where grass meets the rock, I have been trying for some time, but no answer 
Is there a way to have the grass, and rock have different erosion settings?
you could create two network, one having rock style erosion, and one having grass like profile. then plug both of them into a chooser device. also add a combiner and connect both terrains to thet too. for control port use slope selector on the combiner to select your areas and plug the selector into the control post of chooser. thats just one of the ways it can be done. there are many.
thank you I will try this out 