I'd be real curious to see how the design team figured out the demographics for city growth, squalor, etc., and just exactly what those numbers are........

Seems to me, simply cutting population growth in half (at least) for a given level of farm productivity, would go a long ways towards easing the problem.

I, myself, simply keep a set of onagers in every large city (or share a set between cities that are close together) after a period of time, and I don't even bother culturing high-management skills in governors once the runaway growth stage is reached. The best management tool is a trio of onagers and a battle-hardened general to carry out the executions

Shipping peasants to a small city that needs to grow is ok, but can get verrrrry tedious if you need to send lots. Just recruiting peasants for the sake of disbanding them in a fort is a waste of resources, IMHO. I'd prefer to massacre the population and get experience for my soldiers. I often have a wandering band of 'exterminators' with onagers in tow that go from city to city carrying out my 'pacification edicts.' After five or six such executions, those troops start adding experience chevrons pretty quick....................