Came to this through the index thread.
"Lucas: Well, he is a teacher, not a real Jedi. Understand that?
Kasdan: I understand what you’re saying, but I can’t believe it; I am in shock."
THis made me laugh for some reason
As I see it, the idea was that Yoda and Palpatine are “masters” while Vader and Obi-Wan are “knights”. “Knights” use lightsabers and tend to join the action while “masters” prefer giving orders and don’t need lightsabers because they can use The Force itself.
Kind of like a Feudal Lord and their vassals?