Kong is going to win because he is the under dog. It's just how American cinema works. The funny thing is they think we will be surprised. "Ha! They will NEVER expect us to have the under dog win!!!!1" like it's somehow a new and unexpected thing. After all it's not like every single sports movie, martial arts movie and many superhero movie (Batman v Superman, Captain America 3, etc.) Do it all The time or anything. At this point, having the character that would logically and obviously win actually win against an inferior protagonist would be the actual twist.