Battle of Zama

It's a straightforward strategy of attacking the southern cities then turning northward.

When the SE city feels like it can fall without your gens' intervention, move your gens to attack the NE city simultaneously. This way, you can multitask the attack on both cities.

From the lvl 4 city in your way, spam cav and equip them with rams if possible while deploying inf in the city itself to attack the SE target.

If you still have spare resources, spam slingers to thump the war elephants and rescue your allies. This MAY prevent Hannibal from drawing your attention later on and allow allies to help in the attack on the NE city.