Well its kind of difficult to do anything when only three of your provinces can produce any kind of unit. Towns cant even produce their own garrisons of peasants. I have to rely on hiring huge amounts of mercenaries to even get anything done outside of my borders. It leaves me kind of screwed when im faced against larger factions with many more territories to produce units in. I need a larger base from which to produce units. Its that simple. Ill never be able to survive on three units per turn. Not too mention this means the three cities that can produce units will be forced to churn them out continually causing very detrimented population growth. Those cities that cant produce units will grow unchecked into squalor/unhappiness factories.

You dont need auxilia buildings. Just force the player to build their own culture's barracks etc. This simple solution would solve alot of things.