Each level (DH0,1,2,etc.) could include a variety of forms of disagreement, instead of just one. The resulting chart would become a rough guide to their relative strengths: move "up" the chart for better forms, and "down" for the bad ones (eliminate the one-to-one relationship between "DH-level" and "Form of Disagreement").

It would become more comprehensive, but also harder to present in a simple, compelling, immediately understandable way. Not sure if it'd be worth it.