i know that James Cameron wanted Arni to play Kyle Reese but he arranged to meet Arnold in a restaurant to talk about the part and as Arnold walked in James Cameron said something along the lines of "you're a machine" so he cast him as The Terminator instead.
... I'm just babbling have i answered the question u asked ??
Very close again! Actually Arni wanted the hero part (Reese) himself, but when he walked in for the audition, Cameron thought 'holy shit! if this guy wants to be the hero, who do I hire to preform the Terminator, King Kong??!' So Arni was denied the role of Reese, which went to Michael Biehn, and Arni got the role of the Terminator instead. All well in the end!