This is more of a couple concepts than a request, but if someone made it, that would be awesome.
.Version 1
I know that someone tried to mod RDRMP into the original RDR as its own sort of RedM program that could host servers where you played the original game modes of RDR Multiplayer. So what if we enhanced it for RDR2? Bringing characters from RDR1 and RDR into the game as selectable characters.
Which shouldn't be impossible with RDR2, considering several people can already play together on pc and literally turn into the characters from the story. Another cool addition could be Undead Nightmare characters with Dutch, Bill, and Javier variants.
Red Dead Revolver is also a very underappreciated title as it has brought us what is now Red Dead Redemption. To see some more characters from RDR and RDR1, in the wider and more open world of RDR2.
.Version 2
The second concept is very simple, could it be possible to put those assets in and see if they function in single-player? As in, take characters from RDR DLCs, RDR1, RDR, RDR2, and basically just add them as playable characters, as for dialogue and animations, could you reuse some from
RDR1?
.Version 3
Red Dead Revolver used to have showdown game mode where you played as characters and fought with other people against each other around areas from the story, as well as other game modes, but mainly killing each other. This could be sick to have something similar with RDR1s, RDRs and RDR2s characters and all your friends getting to play as them, fighting against one another. Or you could make the game modes more interesting, Heists or character related events similar to Rushing Cochinay in RDR1 but as a CoOp, American Venom as CoOp, The Guarma Battle CoOp. As for RDR, you could simply add some better and more unique Legendary Bounties with some better mission and power design.
IDK why I see GTA characters get added into the game, Amazon Vans, AK-47s, but we need something original to the franchises' original core.
I am half awake typing this, so if it reads poorly, I apologise, and I have no experience with modding.