The only thing that doesn't make sense to me about Bernard being a replica of Arnold is that nobody recognizes him as Arnold. I understand that Bernard wouldn't recognize himself as Arnold because of the rules with hosts. However, you would think someone as well known as Arnold would be recognized by other people working for the same company. Maybe Arnold uploaded his consciousness into a host or even Bernard, but I find it hard to believe that Bernard looks just like Arnold and nobody is aware.
Totally get the recognition thing, but Arnold "died" over 30 years ago. My recollection is that the MIB would be the only guest that would recognize him - possibly. Ford is the only other non-AI that has been around the park for that long, no?