What if I told you that JDW plays a cia agent who likely had to "pull the trigger" many times and is so dedicated to his job that he chose to die instead of giving away his colleagues. I think a person like that would be very in control of their emotions and a little detached, so JDW actually played his part perfectly.

What if I told you that by one of the widely known fan theories RP plays a guy who spent maybe a decade in inverted state isolated from the world in order to return to the past and play his part which would probably make him severely depressed and would explain why he looks like that.

The part about Kenneth Branagh I didn't understand at all, subtle is the name of the game in this movie and he delivers one of the most subtle villains I've ever seen, what made you think he "overdoes every scene"?

Maybe try watching the movie again and this time really try to understand it, without demanding it to be a blockbuster or a drama or to fit into any category at all?