I'm not objecting to your comments, merely debating . . .
I could see him (Stewart) better as Warden. I'm sure Patrick could play Holt but I can't picture it... maybe I'm used to him playing somewhat sympathetic characters (Picard, Xavier).
Did you see Stewart in
Conspiracy Theory with Mel Gibson? I certainly couldn't wait for him to get his comeuppance.
I picture Milos as a little, round-faced mousey guy (there's an actor's face I see but can't place the name). Think Jason Alexander as a real perverted little creep (oh, he already played that role?
I don't want Jason to play the part, but he has somewhat the look I'm thinking of. Or maybe an evil Phil Collins.
There's a name I hadn't considered. Jason plays scum fairly easily, yet I imagined Milos taller and thinner. That's why I pegged Buscemi, who thrives on the marginally sympathetic roles. At first, I had just a smidgen of sympathy for Milos, trapped by his own lies, but just trying to survive. Then they put him in charge of Joshua and . . . nngggg! Nasty Donaldson, bad Donaldson!
As for Williams, good directors get exactly what they want from him.
One Hour Photo is a good example.
Awakenings with DeNiro is another. Hashi is a schemer, an imp, highly competent, and, a surprise to everyone including Hashi, loyal. Not that much of a stretch for Robin.