It is astonishing to realize that Disney allowed his story sketch artists to work in a graphic style that was comfortable to them, and personal.
Sometimes those sketches were mere character animation poses, other times the whole background scenery was included. It was up to the story sketch artist to put down on paper what would communicate best to Walt, the animation crew, and eventually the audienceThe opening scene from Robin Hood by Ken Anderson.
Not sure who boarded "How to Ride Horse" from 1941, but you can see that this story artist was all involved with Goofy's animation business.
Disney's first features were all about light and shadow, so the story sketch artists rendered the environments as well as he characters.
James Bodrero boarded the entire Pastoral sequence from Fantasia in color. It helped to visuals what the final film might look like.
Marc Davis did story and character design work on Bambi for quite a few terms.
I think Bambi's characters work, of cause great was hand out.