Diocletian's New Tax Structure

In order to run a proper army, there were certain things a general learned by heart. Diocletian simply took this understanding and blew it up to an empire wide level. Since the money was no longer any good, diocletian just added up everything the imperial government required to outfit its army and bureaucracy for one year. He then ordered his subjects to supply him with what he needed. But of course, the regions of the empire did not produce goods and services on a uniform basis. One city may specialize in textile production with nary a pig farmer in sight, while another may have abundant wheat fields but no brickworks. So you couldn't just divide up the list and demand