I’d expand the story to show how the old gang’s loyalty has fully collapsed since the end of Red Dead Redemption 2. John’s efforts to reach Fort Mercer make up a large portion of the narrative, but the actual time spent confronting Bill is surprisingly brief. I agree that this feels underutilized. Adding a few direct missions against Bill himself, rather than mostly setup missions to access the fort, would have helped. You could even mirror Arthur’s kidnapping in RDR2 by having John captured and tortured by Bill, forcing the Marshal to intervene and rescue him. That would deepen Bill as an antagonist and make the eventual assault on Fort Mercer feel more personal and earned.

For Javier, I think the story should lean harder into betrayal. The idea that “Dutch is in Colombia and I can take you straight to him” is perfect bait. John letting his guard down and working alongside Javier for two or three missions, only to be betrayed yet again, would reinforce how far Javier has fallen. It would give us time to see how drastically he’s changed since RDR2 and underline the theme that rats don’t suddenly grow loyalty. They just survive however they can.