So you want a full assed socialist bureaucracy? Which is what empires need to thrive on.
Not necessarily. The Mongols had a pretty simple 'bureaucratic' system: leave the current bureaucrats and rulers in place, demand a $#!#load of tribute.
Doesn't add anything, really, to the bureaucracy, except a layer of tribute. Which is just another tax.
Not that I want ANY bureaucracy in place, mind you.