Someone's probably suggested this before but for Red Dead 3, why not set it towards the end of the Golden Age of Piracy? They expand the map every game, why not make it so rather than conquering the frontier, you conquer the waves? It would be easy to add a number of places inspired by world cultures, the drama writes itself and with multiple endings, and the core of the game, exploration and making your way in the world, would still be there. Hell, maybe the main character could be an ancestor of someone from the first two games. As far as boats go, you could have a slow upgrade system where you purchase more and bigger boats, add more guns and cannons, do trading rather than hunting, etc. I know the game is quintessentially American frontier, but a good number of pirates like Anne Bonny and Blackbeard set out from American shores. It's an age that deserves a game like RDR.
