Something like you want to do would most likely need to use Mockup templates for different house designs. There would be a Mockup for each house model, The mockup templates would have six smart object layer to be populated with your six design elements. I do not think you will be able to dynamically create Random House mockup templates and populate them with random desgn element from your six design element type sub folders. My Mockup Scripts will populate a House mockup templates from six sub folders. The sub folders file are populated in file name sort order. If you scramble the file names in the sub folders population of the designs population would be randomized. So my script "PopulateAlbumPageMockups.jsx" would populate your different house mockup templates album pages with randomized elements. If you have 6 house mockup house designs each sub folder would need to have 6 design files. If you have 50 designs you would need 50 mockup templates.