The rad has push pull. The pull fan is behind the rad and can't be seen. What you are seeing is a shroud. It allows the push fan to get airflow to the center of the rad.
I have an I7 950 and 2 GTX 480s, extremely hot running components. I wanted the challenge of getting 480s to run cool and quiet without putting them under water. It took a lot of testing to get the airflow just right. Today's components run so cool you wouldn't need all the fans but it was a fun build at the time.
Sorry, I didn't have a good enough look at your system, I didn't realise you had tri-channel ram (hence nehalem). So yeah that is reasonable I guess.