Preferred
I too like the background choir / atmosphere aspect of the "Battle of Zama" theme but believe the overall quality and ambience of the "Rome goes to war" far superior.
However, I also believe that if this is intended to depict Rome, the intent of the score would be better served with more of a Militaristic / Imperial feel. When listening to this theme, one's mind more readily turns to the exotic east. Point in case, I believe the film Gladiator use a similar score for the segment set in Africa.
my2bob