Triple Frontier had a more than impressive cast for a Netflix movie, but the original cast could have been even crazier. Bringing Ben Affleck, Charlie Hunnam, Oscar Isaac, Pedro Pascal, and Garret Hedlund together as an elite team of former soldiers is one of the highlights of the film, as their chemistry is the core element that makes the movie work, but they're hardly the first (or second or third) iteration of the cast in Triple Frontier's long road to the screen.
Originally starting development in October 2010 at Paramount with the name Sleeping Dogs, Katheryn Bigelow and Mark Boal were going to team up again as director and writer after their Oscar wins for Best Director and Best Original Screenplay, along with a slew of other awards including Best Picture for The Hurt Locker. When production didn't come together quickly, Bigelow moved on to other projects and J. C. Chandor came aboard to revise Mark Boal's script and see the movie the rest of the way through production. Bigelow is ultimately credited as an Executive Producer for her early work on the film.
While Bigelow didn't get very far into production, Tom Hanks was officially cast and Johnny Depp was in talks to play lead roles, presumably Tom 'Redfly' Davis Miller and Santiago 'Pope' Garcia - the roles that ultimately ended up being played by Ben Affleck and Oscar Isaac.
After Chandor came on to direct, Will Smith entered talks to play a lead role alongside Hanks, presumably replacing Johnny Depp as Pope. Smith would eventually leave due to scheduling conflicts, and Depp re-entered discussions, although both Depp and Hanks would ultimately depart when the film still didn't take off.
In 2017, the project finally started moving again, as Channing Tatum and Tom Hardy signed on, likely as the brothers, William and Ben Miller, but it's possible they were also intended as Redfly and Pope. Mahershala Ali also joined the cast, presumably for either the role of Pope or Francisco 'Catfish' Morales, who was ultimately played by Pedro Pascal. Adria Arjona also signed on as the first member of what would ultimately be the final cast.
In May of 2017, Paramount entered talks to sell the movie's rights to Netflix and Ben Affleck and Casey Affleck entered talks to replace Tom Hardy and Channing Tatum, who left the project weeks before shooting was set to start over creative differences. Since Ben and Casey are brothers in real life, it's the most logical they were initially brought in to play the Miller brothers the movie, even though Affleck ultimately ended up cast as Redfly, but casting reports are unclear, but it's also possible Ben was always eyed as Redfly and Casey was Pope. The other possibility is that Redfly and Pope were also brothers in an earlier draft. Regardless, the Afflecks would also depart and Mark Wahlberg entered talks to play Redfly as the film's cast finally began to fill out with Hunnam, Hedlund, and Pascal all coming aboard.
With days left before shooting was set to commence (again) in March 2018, Ben Affleck returned to the project in the role of Redfly with Oscar Isaac stepping in as Pope and the rest is history.
The final product worked out great, but with a number of alternate versions of the movie out there, it's impressive so many big names were attached at one point or another before finally ending up on Netflix. It's equally impressive that a movie could go through so much drama in its path to production before ending up on Netflix but still maintain its big-name star status and get a positive reaction. Hopefully, the story of Triple Frontier will help signal that, in the age of Netflix, "development hell" is no longer a place good movies go to die.