Fruitbat, when I read OUTLANDER (which I loved, loved, loved by the way), I thought the SAME thing. But I'd also thought what Jason voiced in the interview: that the role was too close to Tavington. What Erin and Donna told Jason in the interview was pretty thoughtful, though--Jack Randall actually is an interesting role, because on the SURFACE he looks one dimensional, but then after you get to know him in the story his motivations towards Jamie Frasier are far more complicated than first realized...there's a big twist there. And also, there's 1940s identical version but way nicer Jack Randall to off play the horrifically evil Jack Randall.
It would have been a nice, juicy part for Jason, actually. And he's still young enough to play it (I think).
I'm looking forward to LONDON FIELDS now that I know more about it--it sounds cool!