LB is a bit more of a priority than you think.
1 undersized LB and 2 LBs coming off serious injuries in a position that demands speed is not exactly the way to build a strong front 7. Spikes and Crowell may never make it back.
in a weak LB class, don't be surprised if Bills take Patrick Willis with their first pick.
Weak LB play in filling holes is why the run defense was so bad. They could use another big body to play the nose, but lack of quality LB play at the point of attack is a much more glaring need.