I think there's some miscommunication. I didn't have any problem connecting one of the 4 pin. Cause they can be split.^^So how did you connect it without splitting it apart.
I was saying that two 4 pin 'cables' are joined in a very strange way, such that it's not easy to take one apart from one, thereby negatively impacting cable management. Look at the image again.
*i.imgur.com/zTDs7Qo.jpg
Two wires from each 4 lane cable are splitted into both 4 pin plugs.