Management Consultants

We took their advice - UK government got the management consultants in and surprise! surprise! they advised us to cut the number of staff, because amongst other things it improves productivity per employee. What I don't understand is do we assume that all the staff we now think we don't need were idle? Because if not, won't we have to employ lots of management consultants to do the work that we used to have staff to do?
Reminds me of the staff cuts in the commercial sector in 1990s - the commercial world kicked this cook-book consultancy out so they had to come looking for some new mugs!