Centralise or federate, and who decides what afterwards.
Finance wants the savings, the business units want their autonomy, and the discussion is now more about who owns what than about how it should work. The question underneath is narrower: which decisions genuinely need to sit in one place, and what the rest costs in coordination. Once that is decided, the rest can stay where it is.
An OD Verdict on what you already have, usually in band A.