Not sure I understand. What would be stacked in the first chart you describe? If it's the sub-categories that are stacked, I believe that's what I've rendered h

Not sure I understand. What would be stacked in the first chart you describe? If it's the sub-categories that are stacked, I believe that's what I've rendered here. If it's the top-level categories that are stacked, it's not really a bar chart at all; there'd be only one bar. Either way, you'd still be comparing animals to viruses to plants with one-variable-dimension objects, and you'd have the same problem. The topmost categories simply vary too much in size.