I personally wouldn’t want one with Jack. By then, it wouldn’t be the Wild West era anymore so the game wouldn’t have the same feel to it. I also feel as though his story is done.
Although Micah is despised by many, I think he has a really interesting past and view on life, not to mention that he’s also a highly skilled gunslinger. Lots of potential there, in my opinion. One about Javier’s past with him involved in revolutionary activity, killing the military officer which led to his exile and then the actual escape from Mexico itself would be really interesting too.