RE: vision for scrutiny
In addition to the usual CFPS 4 Principles of Effective Scrutiny you might also want to look at the 7 "Success Factors" identified by the Wales Audit Office. I can provide further details if you contact me but they basically said that Successful Scrutiny should do stuff like Get the right outcomes; Secure Commitment, Focus on the right things etc.
You could even have some fun with this with a Judging Panel of members set up to see if Scrutiny had the"Succ-X Factor!"
(I would be happy to sit on the Panel with Cheryll Cole as a Critical Friend...)