Michigan has lost two key recruiters off its defensive staff to it's top rival the last two days. Not only is that a bit strange, its also a hit to the staff.
Staff changes are very common each year, situations like Fred Jackson who was Michigan's RB coach for 150 years is not the norm. Harbaugh is very respected in coaching circles and hires strong coaches young and old, so it's not a surprise that his staff gets jobs each off season.
I actually thought Michigan could have kept both Mattison and Washington with a new title and few extra dollars.