We're not getting 2 Cassians. We already have one Cassian, and then Cassion 2.0 is probably the journey character (much like JMMW).
So that leaves us 4 characters for the other 2 episodes of the era.
Kleya is definitely going to be a character. She was a central part of the story.
And if we're getting a second version of Cassian, then it's only right that we get Bix.
Syril is definitely a good option, as he too is a part of all the madness on Ghorman.
(Jokingly, I would say 'Well, you can't go anywhere with Syril without his mother being there' - Her first special "Passive Aggressive Nagging")
And I'm thinking we're going to see Melshi as another Rebel Fighter.
Though, this begs the question of team comps.
- Will we see a re-work of Luthen's kit, so that Kleya and Luthen can work together? If Cassian 2.0 is the Journey Character (and possible 'lead'?), then Luthen needs to have his kit altered a little? Or will it be: Saw + Luthen + Kleya + Bix + Cassian 2.0? Though, if that's the team comp - that sort of negates Melshi as being a character.
- Will we see a re-work of Krennic, so that he can be with Partagaz, Dedra, and Syril? Possible team comp here: Partagaz (L) + Dedra + Syril + Krennic + Death Trooper