In an interesting piece of casting in the HBO show "Deadwood", the
actor Garret Dillahunt was cast in two important roles: first in
season one as Jack McCall and then in season two as Francis Walcott.

I'm am interested in finding any commentary from the cast or crew on
the motivation or reaction to that choice.  Failing that, a pointer to
a spirited discussion of this on fan sites would be interesting as
well.