Thinking back on my earilier comment regarding the prominence of Schulz in the movie, I've been wondering if perhaps this movie is really about his journey. If you look at the movie as having a plot of Django getting his woman back the movie definitely makes this progression from start to finish. However in terms of character growth and change I think it might be argued that this is where the movie may really be more about King Schulz.
Django may provide the physical conflict but the dramatic conflict really resides with Schulz. Especially with the dog scene, we see that Django is who he is at that point yet Schulz was still in motion.