No sweating here insider. No need to take my word for it that MAS comes under PMO, just check out the official link. Happily enough, you'll also be able to verify whether "all ministries report to PMO" as you so ignorantly claim: http://www.pmo.gov.sg/AboutPMOffice/

It's a pity you aren't an AO or civil servant - your willingness to provide strident "analysis" on the relative importance of scholars in statutory boards and ministries without actually being there is a characteristic that will put you in good stead should you decide to join. AOs and civil servants LOVE to do this.

And I'm not even going to start explaining about MOF and its utter lack of a formal relationship with MAS.