This is so weird how the wheels are set in motion.
When the Bills hired Mularkey from the Steelers to be their HC, the Steelers gladly let him go and replaced him as their OC with their then TE coach Ken Wisenhunt. In fact, the Bills were denied permission to talk to Wisenhunt for their HC and OC opening.
Wisenhunt went on to steer the Steelers to 2 super bowls while Mularkey after two seasons with Buffalo went on to take roles as position coach in Jacksonville, Miami etc.
And now Mularkey replaces Wisenhunt.....