Carthage is always a tough one in siege assaults. The same things that make them so fun in field battles, cavalry, cavalry, elephants and, oh, cavalry, give them fits when trying to get through a breach or gate. I almost always end up waiting for towers too, just so that I can get more of my infantry onto the walls faster. Most of my infantry is crap, but if I can hit them from both wall directions at once....

I used to, once resources built, set up a siege assault army. I recruited many mercs for that army, leaving only the onagers, some peonis, and some long shields from integral forces. Loved spanish, saminite, numidians, barbarians, and thracians for the rest of the assault team.