Standing armies tended to be small for city states, most soldiers could only campaign for the lenght of a season before they had to return to manage their farms or other business. Doing otherwise would cripple the economy of the city state.

The Spartans were different, even weird in that...they too, had to return after a short while of campaigning, but only to keep their Helote slaves, wich did everything to keep the economy going, from revolting. It always seemed strange to me that people consider the Spartans to be noble and dignified