'Williams will replace Gillislee as the second halfback, and the 2016 fifth-round pick from Arkansas has potential as a power back. But the real interest in the Bills backfield will be how they deploy both DiMarco and Tolbert, two veteran fullbacks with wildly different characteristics. With the Falcons, DiMarco was a great blocker, but he would also flex from the backfield to the formation as a receiver everywhere from the slot to out wide.'