Imagine if these guys all went on the adventure with Luke; I'm guessing that Fixer would sneak off of the Falcon with his girlfriend while everyone else was busy rescuing Leia, and those two would escape into hyperspace after stealing Vader's TIE fighter. They would never be heard from again. Windy would be Luke's wingman along with Biggs in the final Death Star assault, and would chicken out while Biggs got fried by Vader in his conventional TIE fighter. Windy would then circle around and destroy Vader's TIE, and Han Solo would not come back to save anybody, having tried to pay back Jabba the Hutt. Chewbacca however would return in an empty Falcon, having left Han in a lurch back on Tatooine, where he would have to be rescued in a later film.