Ah! but the Government committed itself to reducing the size of the Civil Service. They are doing it by both contracting out and buying in Consultants. The MoD was previously accused, mainly by the Treasury, of not being "commercial" enough in its operations. By using a consultant, that accusation no longer stands.
Something that grips me about having Consultants in is the way that they don't usually understand how the MoD/Military work. Instead of them learning our formations and organisation, though, we adapt to become more understandable to them. Them adapting takes time and costs money. Look how many Head Offices the MoD now has and how few "management" docments are drafted in JSP101 format.