[@Cyclone]

Yeah, Bronze Age armies weren't all that grand now were they? It tended to be, like [@Muttonhawk] said, several hundred to maybe a small thousand at most. Not to mention the population density during the Bronze Age was not very dense at all and with Empires there would be some centers scattered around with maybe one large city at most, yeah?

Edit: Kho brings a valid point though, the mongols fielded massive armies and they didn't rely much on agriculture