You bring up a good point on Dantonio having to be be better than the other bunch. He is a better developer of talent than the other three. Motivator too. But, you need Assistant's that help support it all. MD might be lagging a bit in that area for the first time in forever. Loyalty can be the death of many Head Coaches. Urban paid a dear price this last offseason. It has hampered Harbaugh as noted. Thankfully the O-Line change finally happened.
Sidenote, I follow the offensive coaching staff at Michigan State very closely. Brad Salem recruited and coached a family member of mine at his last stop. I am genuinely intrigued with his career path and success with the QB's. I will be curious to see where he lands in any shakeup.