I learnt about -ai, and ran a campaign yesterday. I was following the Julii so I didn't manage to reach the conclusion since Spain eliminated them on their way to conquering all of Italy and starting on the Brutii's stuff in Greece...
In an earlier game I was following Macedon, and Thrace demolished them. In the second game Macedon fought Thrace off and Thrace ended up just fighting Scythia until the Brutii came. I feel like they are nicely balanced, but Spain need work!