Reread it. It says "New Orleans has been looking for somebody who can take some of the load off of Kamara" it doesnt say they are looking for a player like Kamara. If anything they were replacing Mark Ingram who had a 4 game suspension to start the year.
Just admit he got beat out by Dwayne Washington. You said there wasn't a Washington vs. William's conversation on who to keep but that was exactly what it was. They cut Williams to sign Washington.
There is a reason he rode the bench when Mack and Wilkins were both back healthy.