And neither is he, for he is but one of the other celebrities we had for disguises... Jean Claude van Damme was another design for the T-800, Edward Norton was another design for the T-1000, and Sigourney Weaver was another design for the T-X.
He too was a prime selection in a design for a relevant disguise, but in the end, Schwarzenegger's sometimes awkward delivery and blank stare compensated for the metal endoskeleton disguised.