You're talking about 2000 year old technology and client states that were continuously conquered over and over by various "empires" throughout time. How does that compared to air craft carriers, fighter jets, nuclear weapons, and alliances with world super powers?
A roman client state couldn't send thousands of troops on air planes to Afghanistan in less than a day to support them like what the US has with the UK or Australia etc.
Entire Roman units would get wiped out by disease and lack of supplies with too far of a walk to get resupplied. Meanwhile I was walking up the side of a mountain in the middle of nowhere in Afghanistan drinking Gatorade and Red Bull.
If you don't see the difference between old "empires" and the way societies are formed in 2015 I don't know what else to tell you.
