When I first read the title of this thread, I immediately pictured a 2 foot elephant head with huge tusks with spikes attached to aid in killing Rohan soldiers. Makes more sense now that I've re-read it. There was a guy on this forum that did custom 1/6 figure head sculpts. They were pretty amazing if I recall. Maybe some of the other guys can chime in with that fella's name as I can't remember.
They are using the FaceGen software, which basically means that the likeness is in how the piece is painted, not the actual shapes of the face sculpt. This is an example of how Schwarzenegger looks when using that software. As you can see, the sculpt itself is very basic and barely resemble the person - it's all in the paint application... and that's shoddy at best: reminiscent of dot printing.