In an interview with Vanity Fair, Justice League and Batman vs Superman screenwriter Chris Terrio opened up about the production issues on Snyder’s DC films.
The writer explained that, despite writing the team-up of multiple characters who would each have their own films, he was “not consulted on the order” of their release. Warner Bros. determined the release order of the universe with no “thought to how the world was constructed”:
“I was not consulted on the order of the films, even though I was the person writing Justice League. They just determined that it was going to be Batman/Superman, and then Wonder Woman, then Justice League, and then Aquaman. So there was never any thought to how the world was constructed before they issued this edict. They said, ‘Conform to this schedule.’”
When asked to clarify how that complicated the writing process, he explained the “Wonder Woman script wasn’t even finished when [he] wrote Justice League.” Terrio went on to explain he knew virtually nothing about the content of the solo spin-offs, meaning everything he wrote had to be “from scratch”:
The Wonder Woman script wasn’t even finished when I wrote Justice League. So I had no basis to write Wonder Woman other than Batman/Superman. Themyscira didn’t even exist. I was never shown anything on the page for it. I didn’t know whether people could talk underwater. That was a thing that I had to ask because I didn’t know if I could do underwater scenes with Aquaman and Atlanteans. It was all just from scratch because there had been no [solo] character films.”
Terrio supported Zack Snyder’s previous claim that Warner Bros. chairman Kevin Tsujihara mandated Justice League to be more comedic than past films, and under two hours.
This left the writer three new heroes to introduce, a Man of Steel to resurrect, and “a long game mythology” to create, all in under two hours. Terrio went on to say he was unsure “how you could do all that in under two hours,” suggesting that “maybe the 2017 release proved that you couldn’t”:
“So Justice League needed to establish three of the characters; it had to create a long game mythology for the DC Universe. It had to resurrect Superman because he was dead at the end of the last movie. I just don’t know how you could do all that in under two hours. Maybe the 2017 release proved that you couldn’t.”