@Gnoster ICFZEbra asked about roleplaying multiple characters and Swen himself answered
You don't have to be disappointed. You can play like what you describe. The only thing you can't do in the default setting is evolve the relationship but I imagine that we'll leave the option in to role-play that too, because we already have it and it's what we're using to play/test the game.
Read the post you're referencing and I agree, I also read Swen's remarks as it will be possible to have complete freedom in creating all 4 characters and roleplaying them ingame. It does make me confused as to why they didn't explain both methods in the Kickstarter update 11 though, will have to see what the end result becomes. Hopefully it is both, so we all can play however we would like.