The free harbors element is more valuable now than in vanilla, as it effectively eliminates a source of unhappiness if city placement is managed well. That helps Carthage's early/mid game quite a bit.
It is pretty much comparable to the old Meritocracy policy, which is now gone. Yes, it helps, but it's not enough. And the same effect can be achieved with one policy from Might branch.
Gazebo said:
The UA regarding mountains is somewhat cheesy, sure – if nothing else, it might be worthwhile to reduce the damage penalty to -15 for Carthage when you end your turn on a mountain (to make army movement over mountains more viable).
It adds nothing except flavor. It can lead to some fun things, like roads over mountains but the other part of the UA is there to make sure that you need no roads. It is a very minor thing which has close to no impact on the game. I have never seen anyone say "I won the game because of crossing mountains". And overall even if you do cross mountains you do it in one turn, so reducing the damage would only allow workers to build roads there quicker? This is such a fringe case that it's simply bad.
Gazebo said:
The Quinquereme is unlocked a few techs before the Trireme, and is simply stronger than the Galley, meaning that Carthage can own the sea from the beginning of the game up to the dawn of Caravels in the late-Medieval period. That's pretty big for a UU, far more so than most civs. That alone makes Carthage potentially very potent.
Quinqueremes won't take any city, maybe except something with 1 population and no walls - simply because they are a melee ship. I tried accomplishing something with both UUs a couple minutes ago when Denmark and France DoWed me at the same time - new patch downloaded, so 16 strength. Results:
- I tried using African Forest Elephants and Spearmen against a 5 defense Danish city. I spent 4 turns bashing with four units until they built walls and my units started hurting themselves more than the city. I only took half HP. To compare with the previous patch I tried playing Poland and I took an Aztec city with an archer and a warrior. It didn't build walls though. Yes, I know Elephants get the penalty against cities but they still had double the strength of the city.
- I tried taking a coastal city of Nappy with Quinqueremes... Since only two could attack each turn, they also got destroyed accomplishing nothing.
So the benefit of quinqueremes could be a defensive advantage at most, and still it doesn't last that long, as with the advent of the Galleass they start to lose. Cities have so much HP that melee units/ships simply cannot take them. Other UUs let civs go on a conquering spree. All the Quinquereme does is beat Galleys and Triremes (which also won't take any cities).
Gazebo said:
To conclude, naval civs are risky by virtue of map types and the settlement habits of other civs, however I don't think that Carthage necessarily needs a UB. Adjusting their mountain trait will, I believe, round out their unique play-style enough to make them quite viable. I think we can safely say that Carthage is at the 'fiddling with numbers' stage of the leader balance project (as with most civs). In fact, to jump off topic, the only civ that I see needing a complete rethink is Indonesia, as the AI simply doesn't know how to use that UA (and that, by itself, weakens Indonesia a lot). My solution for that is to remove the 'on other landmasses requirement of their ability,' but that's a point for another thread...
G
Carthage should definitely be an economic civ with trade emphasis and two UUs just don't cut it. Also, they way it is now the only long term advantage Carthage gets is 3 gpt per city, which is pretty poor. Yes, they have early game defensive bonuses and a gimmicky mountain thing which is more or less useless - it is only there for flavor.
Neither of the UUs is actually strong, as what ultimately matters is taking cities. Prevalence of spearmen earlygame makes elephants quite poor and the great generals bonus is wasted on an economic civ, just doesn't fit.
Overall, the only real advantage Carthage gets is the free harbor, and it is only significant in the early game. Since medieval they are a vanilla civ with 3gpt per coastal city. I would certainly not call that viable nor potent.