doubleofive said:
I think it comes down to that in ANH and ESB we're following basically the "white human" cell of the Rebellion. In RotJ all of the cells combine to make a united front to attack the DS2. That's the impression I get.
That's also the impression I got. Because you see nothing but humans until ROTJ. Then you have the fish, and then that weird co-pilot with Lando... Honestly, now that you mention it, there weren't enough aliens represented!