Ok, I just looked up info about Arkham, and something stood out.
"Jeremiah was not one for "compassionate" healing. He relied on the teachings of B. F. Skinner, and used negative reinforcement to cure his patients. Even the most dangerous of inmates soon began to fear him. "
Clancy Brown is an intimidating guy who could act just as frightening. Sure, he's a big guy, but that doesn't mean he should be restricted to playing the thug. He's got the acting chops to be a slightly mad, intimidating, aging doctor. Sure he's bigger than Arkham, and a little younger, but the character could still be the same. Brown would nail it. Plus, I mean, Clancy Brown isn't exactly a spring chicken. He's getting up there a little bit. Look at him on Lost.