I have seen him in The Outpost, Thor, and The Other Guys. He was a good actor in those so I see him making Firefly a very straight forward mercenary type.

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Klink: Schultz! Where is that radio?
Schultz: They didn't tell me!
Klink: Find it at once!
Schultz: Jawohl, Herr Kommandant.
Klink: Hogan! Where does that voice come from?
Hogan: From the accent, I'd say England.
Hogan's Heroes" (1965)