"recreating the famous Battle of Carthage." It's a balancing act, always.
They also disclose letting us control up to 40 units at a time, a tactical overview map for 'battle orientation' and where they're focusing next. I wouldn't have the Gaul to spoil it for you.
In the dev diary, they say how hard it is to be faithful to scale whilst making sure the likes of Carthage "fits into the context of the game." They admit trade-offs are inevitable.
At the end of the video they tease we'll be seeing the Creative Assembly horde meandering around the forests of Germania and Gaul as they turn their focus toward the barbarians. The faction of Carthage has been the latest officially confirmed for Total War: Rome II, which releases exclusively on PC in October 2013.