I think it is a fair comparison. Yes, Lucas had years. But the process is the same whether you take years or months. I mean, does it really take George R.R. Martin 10 years to write a novel? No. He does other things. Other writers have put out about a book a year. Books that are outstanding. So Lucas took 2 years to go from treatment to the revised draft 4 used to shoot the film. And when he was doing the movies, he always allowed a full year to develop the story. Does it really take that long? No. That was his method. But when you get in to the actual process of rewriting a movie, yes, such drastic changes are not unusual. They have even extended it into post production with reshoots and even late rewrites of the story. Rogue One had some major changes late in production and some major reshoots. The final movie is not the same as the shooting script. It is a gradual process of dialing in the story that is used on a lot of hollywood movies. And novel writers also do it. Sure you find a few writers who know what they want and their final draft is very close to their first, but other writers will shuffle scenes around, make major changes, and the journey from rough draft to final draft produces huge changes to the story. For one writer a 100,000 word novel might have included 120,000 written words (deletes and revisions), for another it might have included over 1,000,000 words written. And scripts more often than not tend to follow the later path and little from the first draft actually ends up in the final movie unchanged. And time is relative. It isn’t how fast they write it, it is how many drafts and how many changes are made. A good writer can churn out a 120 page script in a week and might do a couple of drafts in a month. Other writers might take a year to go through the same process.