The Rock shouldn't work a program with Kennedy for the same reason he shouldn't work a program with MVP.
I'm not sure Orton's a better choice, because he's had a win against The Rock and Foley, and while I know it wasn't a singles win, I don't think there would be any bigger impact to a solo win. Plus, if he can't capitalize with all the pushes he's got, he deserves to be killed.
The only logical choice is Shawn Michaels.