Ah, got ya. I agree with you on the scale being smaller, so it makes sense to use those model guys, they're a good mechanic choice for the piece too, and without paint they pass easier as SW universe. A pic with a SW or Joe figure definitely will give the best idea, but that thing is really big!
Okay. I don't have a lot of Joe figures lying around, but i had a MKII and War Machine on a shelf, and Scarlett from the ROC.
Here are some pics of the figures with the ring to give you an idea of size.