Somewhat off topic, I try to take out Patavium ASAP. That city is like the most fertile I've ever seen. If the Gauls keep it they'll soon overwhelm middle Italy. The other nice thing is that you can jack up taxes to Very High and STILL have 4.5% growth rate or better. I always help keep the population in check by using Patavium as a source of settlers. I'll pump out Peasants or Town Watch and send them to underpopulated cities (like Segesta or Caralis), then disband them to artificially boost population there. Also, I think when you train a unit and disband it, turning the troops back into civilians, they are ROMAN civilians, and as such, help dilute the negative Culture affects of newly-occupied cities.