Change Management  big, broad and transformational requires every helpful resource possible, but not all resources. It requires leadership but not too much control. It requires energy and motivation, but with the right skill set and competencies at the right time ("championing" has gotten old and tired for stakeholders and those marked to be the cheerleaders) and it necessitates a balance of internal and external.

High level change consultants if they are effective, are focused on business objectives, value for the client and clear end states. Internal resources, change agents and the PMO along with the stakeholders, know the path (internal politics, established processes of communication and collaboration, reporting structures).