The entire Rhino battle reeked of studio interference.
Studio: "He needs to fight a character with powers similar to his own, but bigger and meaner than himself, just like at the end of the original Iron Man and Incredible Hulk."
Director: "Uhhh, we really don't have the budget for that and it doesn't really fit the tone of the rest of the film."
Studio: "Original Iron Man and Hulk finale. Do it. Now."
Director: *sigh*
Studio: "He needs to fight a character with powers similar to his own, but bigger and meaner than himself, just like at the end of the original Iron Man and Incredible Hulk."
Director: "Uhhh, we really don't have the budget for that and it doesn't really fit the tone of the rest of the film."
Studio: "Original Iron Man and Hulk finale. Do it. Now."
Director: *sigh*