Prepare for the most hardcore geek argument you're likely to see/hear on the subject...
This is an image from the end of Argo, directed by Affleck, who was allegedly a runner-up in yesterday's great director sweepstakes. Notice anything wrong?
How about now?
If Kevin Smith is anything in real life like his characters, he needs to give his pal a hard time about this one. Sure, you could argue that perhaps the kid in the movie is not meant to be smart enough to get all his Star Wars characters straight. But I doubt it - I was that kid's generation, and we knew them backwards and forwards.
Sorry, Ben - confusing Sand People and Jawas is a Nerd Foul if you hope to make a movie in their universe.