Thought I'd add my two cents regarding the carthaginian UU. I'm not certain if there are already any contributions on this thread regarding the unit, I only know Aelf hasn't done an 'official' write up. So........
With the advent of chariots gaining the ablility to crush axemen, it seems the common trend has been to make super axemen. The Numidian cavalry is such a unit. It's too bad the on screen icon has these guys holding spears; they're basically axemen on horseback, gaining a movement of 2 and the same horse archer bonus vs. siege. They enjoy the +50% vs. melee, as all axemen do, however, they cannot acquire the city raider promotion.
While the numidian cavalry is a useful unit, it is not a game breaker. You won't be taking cities with them nor will they make up the bulk up your army. They make excellent stack busters on defense, however, you'll want to attack with these guys when defending your land as they do not receive defensive bonuses. The +50% vs. melee and siege gives them a nice advantage versus any stack invading your lands. They'll still have a tough time with spears, however, with a shock promotion, they are even (+75% melee vs. +100% mounted = +25% mounted; 25% of 4 is 1 totalling 5, the attack value of the Numidian Cavalry).
Other advantages include starting with flanking 1 and as Hannibal is a charismatic leader, promotions now occur at 2, 4, 8, 13, and 20 XPs. Having this UU come out of the gate (no pun intended) with 11 XP is doable, making each unit one victory away from it's 5th promotion. And the flanking promotion will carry over when upgraded to a knight. 5 promotions for a knight is a formidable unit so lots of this UU are a good idea.
I feel like I have one more thing to add but can't seem to recall it.