HBO has posted an interview with Matthew Macfadyen and Nicholas Braun talking about being an outsider among the Roy family.
On joining Succession:
Matthew Macfadyen: Working on an American show and playing an American role gave me a chance to do something I hadn't before. As an actor, you don't want to get stuck in a rut, so Succession was perfect for avoiding that. It ticked every box.
On playing Roy family outsiders:
Matthew Macfadyen: Most people don't know what they're doing, in general. People go to work every day and tell themselves and their colleagues, "Oh yeah, I know what I'm doing," but in truth, we’re all trying to get by. Even making good television — no one knows for sure what makes a TV show successful. We're all trying to get good people and hope for the best, but there's no formula.
On Tom's relationship with Shiv: