In my opinion having managed the Hoffman Challenge for 11 yrs is to establish a theme or select a fabric and then give participants freedom to work within those peramiters. I believe too often there are too many rules attached to the challenge. That is why I suggested "Architerial Details" and then the detail the designer wants to focus on But Architerial Detail is the base subject. Then I can do windows, the gingerbread decorative elements on house, shingles or tile on the roof.
Now speaking from the judges side.......we need to be able to recognize the design intent of the quiltmaker. Therefore the rules need to be established to assure that.