K. Williams and Cook are the same draft class. Williams was a 5th rounder. His 2025 salary is less than Cook. $11 mil/year is a nice increase for 5th round RB
Williams is a year younger than Cook, 24 about to turn 25, compared to Cook who will turn 26 in Sept. The Rams drafted Blake Corum last year and used a 4th round pick on an RB this year. So it seems that the Rams, like Buffalo, will use 3 RBs.
Williams is about as close a comp as you will find for Cook, so I can't imagine the Bills paying significantly more.