If I understand which slope and cliff you mean, I see nothing wrong. The cliff above is the history of that material. These rocks are eroding fairly rapidly (in goelogic time) to produce such steep, rough cliff faces. The slope I think you are talking about looks to me like a regolith slope derived from mass-wasting of the cliff above. Because this is a tropical environment, such slopes are rapidly covered by vegetation (Hawaii has similar terrains, as does the Sawtooth Wilderness (Idaho, IRC) and many other locations. Such terrains are generally produced by rapid uplift accompanied or followed by rapid erosion, though they are also dependent on the type of rock. While pure fractal terrains are usually geologically questionable, they are a good starting point, and Vue is an excellent program, IMHO. I wish I had more time to use it!