I don't think you simplified too much. The deer looks great and I'd say whatever mindset you had while drawing that one is probably your best bet to understanding how to manipulate structure. I do suggest to try to tier your lines though. Keep your cross contours lighter and your contour lines thicker. Any important lines like gestural lines (even if their "arbitrary") or cross contour could stay thick as well. Kind of like your deer drawing. This just helps with readability for both you and others.