Based on traditional art that depends a little but I see what you are saying and agree. Painting landscapes frequently start as a outlines and shapes, then filling in details, building up textures.
What caught my attention in the Forest tutorial is that the author says it’s mostly about presentation. And when you look at the elements, while their placement requires some general rules as in what you might spect to see in nature, including some perspective decisions, such as he chose to place the largest trees far away, it appears simple to place them. And finally I had no clue just how non-complex the basic terrain shape grid was. However the master texture will require some study.
I remember first looking at this scene, regarding how complex it looked, and I would have never guessed that the terrain involve was so simple. Of course this does not mean I’ll be able to duplicate it, but that is what this is, duplicating to learn. Because natural settings is a significant area of which I am interested in creating. Hope I’m not too disappointed. 
One very cool aspect of digital art is lighting that can be controlled by a few settings changes where in a painting the entire painted surface, the artist must micromanage lighting, considering how light and atmospheric conditions effects the appearance of every object in the scene. Yes there are lighting settings that regarding digital art may seem complex to master, but the work load is handled mostly by the engine, and the artist is just faced with knowing which settings to change and how.
