There are times when an actor is able to make a role their own to such an extent that you could never imagine somebody else playing that part. Stallone as Rocky, Ford as Indiana Jones, the list could go on and on, and included in that list is Arnie as the Terminator.
But then, it was a close-run thing for him to get the part to begin with as studio bosses had somebody else in mind. That individual was no other than O.J. Simpson.
So, why did they decided to go against this idea and give the role to Arnie instead? It seems that the bosses believed that nobody would be able to take O.J. Simpson seriously as a remorseless killer. That does come across as being a bit of a silly assumption to make considering now most people could easily see him as being a remorseless killer.