I'm not saying that it's the crown, but that it has the same design as the crown. It seems logical that someone would make their crown and helm in a similar fashion. (See: Isildur's crown has the wings on the 4 courners, and it's the same design on the helm on the left figure's helm) And also, the sword that is held by the figure on our right is Narsil. While Isildur's sword looks like Narsil, it doesn't have the hollow pommel and the holes at the ends of the crossguard. And it's held by a figure wearing a helm of the same (or very) similar) design to Elendil's helm, that sword is clearly Narsil. And therefore I still think it's Elendil and Isildur. Also, remember, Anarion was never mentioned in the movies, nor was Anor, which Isildur actually ruled (while Anarion ruled Gondor), nor was he mentioned in the Weapons & Warfare book, which might give us a clue that the character Anarion was not developled by the design department and incorporated into the movie's development (because his being part of the story doesn't really change much). Also note that people who'd only seen the movies, but haven't read the books, do not know about the Anarion and Anor. On the other hand, we were shown Elendil and Isildur (along with their respectively distinctive helms), and it makes perfect sense that the film makers were conveying the idea that the statues represented Elendil and Isildur by showing us the figures with Narsil, Elendil's helm, and Isildur's helm. It seems to me that the most logical and reasonable conclusion is that the Argonath in the movie are Elendil and Isildur. Or we can write PJ and ask him like Curunir's Bane said.