Anime is a style, not a fundamental part of art. Just like any other style, if you don't have the ground work laid you will just make mistakes. And no, Bob Ross did not ignore anything. From his biography:
"He learned the technique that would make his careerâthe wet-on-wet (alla prima) oil painting techniqueâfrom television painting instructor Bill Alexander, whose show, The Magic of Oil Painting, aired on PBS from 1974 to 1982. The wet-on-wet technique involved applying oil paint on top of still-wet oil paint, rather than waiting between layers for the paint to dry."
Anime is a comic style that combines mistakes in anatomy to tell a story. If you don't understand how the body works you can't make those mistakes in a purposeful way to get the result you want. Hence why so many people use 3d models to draw over, they don't know the basic anatomy under the drawing they want to do. All you are doing is making your life hard by not learning the way it has been taught for literally centuries.