I would love to see him at Michigan. I think he competes for a spot immediately, although I am more high on Walker than Maylor. Bullock has outgrown 174 and might not even have a spot at 184. If Woodley isn't able to go next year then the best option(s) at 197 would be Bullock and possibly Walker, if Rowley claims 174.
All of this said, I do think Griffith to Michigan is possible, so he would be 174 either way (or Amine). That puts Walker yp to 197 with Bullock and Rowley sitting a season.