THIS Is The Perfect Red Dead Movie
7. What WON'T Work
Let's address the obvious.
No matter the casting, any movie about John or Arthur would IMMEDIATELY elicit heavy skepticism - and possibly outright rejection - from fans. Their in-game performances were perfect. They were so fully realized and so well-developed that it'd be hard for any fan to put them out of their mind. A live action adaptation would be met with a healthy dose of, "Really? THAT'S your Arthur? THAT'S your John? Boo!"
Not only that, but their stories have been told already, and they've been told perfectly. We know Arthur's story, and we know John's story. We love those stories. Why muddy the waters trying to adapt them when the product would almost certainly be inferior?
A story about Dutch's youth MIGHT work, but Red Dead Redemption 3 could feasibly explore that era. Ditto for Landon Ricketts.
A movie about Charles Smith could work, but his mixed heritage would make casting rather difficult - he's half-Native American and half-African American, a very specific combination that narrows the pool of actors to choose from. What's more, Charles expressed his desire to settle down after the events of RDR2. It makes more sense that he'd just go to Canada and start a family like he said.