Distributed Random Object Set Arrays

I have tried using dupliverts to aid me in distributing 18 different rectangular shaped objects that are arranged in group sets of 3 objects to no avail. These group sets of 3 objects must be assigned to a larger highly subdivided surface on each of the faces evenly. Yet the sizes of each of the 3 objects in a group of objects height control must be maintained individually via “mesh edit tools”. The groups must also be “randomly” distributed to each face of the subdivided larger object. I think that a script could be applied to help me to complete this task. However I haven’t had much time to learn python scripting in Blender.

Thanks for any help that you can provide in advance.