I played my first game with him, using Carthage - Chola - Britain on an Archipelago map. As suspected, his Antiquity age feels quite lackluster. Yes, you get a lot of ships, but ships are not very useful in the Antiquity age. On Deity, you will fight at quite a disadvantage and there is not too much you can do to buff ships. And archers and ballistas on the shore are extremely dangerous. The result is that the ships spend most of the time trying to heal. The Carthage ship range upgrade was a lifesaver and after also researching Quadriremes , I was able to make some progress and even capture cities. But I got nowhere near the end of the tech or civic tree, and did not get many Science or Culture legacy points. But that may also be, because Carthage is not very strong in the current balance as they have to buy a lot and everything is so expensive. Maybe I will try Aksum or Tonga with him to see whether that feels better.
But he makes up for that by having a really powerful Exploration age. Naval units are much more useful in that age, and fleet commanders make all the difference. Add in Chola UUs and you get an unstoppable fleet which grows with each victory. You don't even take that much damage, since the initial salvo will usually capture a ship, which then serves as cannon fodder for the counterattack. Which means that you lose quite a few of the captured ships, but will still walk away from a naval battle with extra ships. On Archipelago map, the fleet can be easily converted into a large empire and I brought 110 points worth of treasure resources back home and I think I don't even captured anyone else's treasure convoys.
Modern was then just a mop-up. Starting with 5 fleet commanders (many of those highly leveled) full of ships meant that the AI did not stand a chance. After declaring war on turn 12, I conquered 10 settlements and eliminated 3 AIs in 9 turns (and could even have done it a few turns faster, had I remembered to bring a land unit with me). This resulted in a turn 31 military victory, which is tied with my fastest Modern age victory ever (and the other one was before 1.2.5).