[Soup_DZ]

I believe I covered that in the Color scheme section aka Step 2. It would fall under the blend of the work, or the flow.

"Is the size of the render/object appropriate for the dimensions of the artwork?" <- That's not the same thing as balance.

Nor does it fall under blend. Everything can blend easily, if you wanted it too. But it doesn't mean it's all balanced out evenly. Balance is like the Rule of Thirds.