I found something odd when I started a new game as Rome on H/H. I spent all my money recruiting men in Messana - 2 Hastati and 2 Town Watch. Then, when Hannibal attacked, he didn't assault! He started starving the garrison out. This gave me time to move my Southern legion to Italy and fight off the Carthaginian attack. This startegy not only saved Messana, it got a legion onto Italy with a base to withdraw to and a source of men. I stand a good chance of fighting off Hannibal and the other armies.