Creative Assembly and Sega have recently released the latest update for Total War: Rome II, making this the fourth update since the game's release. This update is the biggest to date for the game with 175 fixes and enhancements that include major AI improvements related to the construction of new buildings, food supply management, creation of armies, technology researches and tactics used during battles, making the AI more organized and challenging. Other improvements and tweaks have been made to diplomacy, missiles, melee units, and more.
The patch will be automatically applied the next time Steam is started for those that have the game and you can click here for a full list of updates in the patch. It's also worth noting that Patch 5 will enter public beta next week with more optimization and improvements to the gameplay, balance, and usability.