The Americans: They are hard to use for games that go over 30 minutes. They don’t have plantations, so once the map coin is gone, you need both factories and the trading posts on coin or your economy will dry up. I’ve won by doing it this way, so it is possible. Plus The Americans get troops by fame (from the command post) and by export (through the consulate). So the need to lean on coin to make most decent units is limited. I typically pair The Americans with The French at the consulate, giving me access to skirmishers and cuirassiers, which help to balance the theme of ranged infantry and melee cavalry to provide the upfront distraction. I use a mix of maybe 20% cavalry, 30% melee and ranged mercenaries, and 50% ranged infantry. The DPS is key to winning, and firing off at villagers that wander by is a great way to shut down your enemy while they are reeling from the attack. Games with The Americans are closer than they should be, but still fun.
The Ottomans: So not having to ever build s villager is nice. But you end up with more of them than you need. I had 25 on wood, and that’s too many. I didn’t need all the wood I ended up with. But they have janissaries and abus guns which are easily two of my favorite infantry units of all time. Plus they have spahis which can tank the front lines and do gobs of damage while the ranged infantry and light artillery do the heavy lifting. This combo is more effective than trying to do the same thing with The Americans because The Ottomans have better DPS units. I also get grenadiers which add a little spice to the front. Cavalry archers do the cleanup for the spahis. This combo is not as fast as The Americans, but is generally harder to stop because of how much damage abus guns do to buildings also.
The Japanese: This faction is so very different from the others. You don’t hunt food, you build shrines and animals are attracted to them. The more animals at the shrine the better resource gather rate they have. Shrines also raise the polar ion cap by 10, so they gather a resource of your choosing AND are a house. The Japanese level by building mini-wonders which are just big buildings with a unique benefit for whichever one you chose to build. They also can level and still produce villagers which is fucking awesome. Samurai are very good in substantial numbers. They work well when given some ranged infantry in the form of ashigaru musketeers and a few yumi archers. There are multiple home city cards which make the musketeers better, and I typically pair them with America at the consulate, because I can ship rifleman and gatling guns. They have rice paddies, which can produce either food or coin, and I’ll typically get four for free from shipments, and just have to assign the villagers to go work them. Those shipments also increase gather rates at the rice paddies, and having 50 or so villagers tasked to them is an easy way to have a rocking economy.
The Portuguese: I like the cassador as an effective DPS ranged unit. I also like how many upgrades they have to ranged damage and to halberdiers. An army of 40% melee 60% ranged is hard to stop. They get a town center at every age, so the fame income is always high. But the lowest cost command post unit bunch is all crossbowmen, which I don’t like. Then the second one is culverins and more crossbowmen. So that’s unfortunate, because they only effectively counter infantry. Musketeers and cassadors comprise my ranged attack, with pikemen and halberdiers dicing people up at melee range. Another all infantry approach, and just as deadly as my other strategies. They have one shipment which improves villager build time, but the multiple town centers helps to increase production rates for your economy. The more villagers the better, since European civs are kinda locked in to slowly making them. I find I’ve been spoiled by this faction; having multiple town centers is awesome. So is not having to pay 600 wood for them.
The French: The cuirassier is an amazing cavalry unit, and when paired with hussars and others, create an unbeatable front of heavy troops. Coureur des bois are quite awesome as well, as they harvest resources faster, and survive longer when pestered. Though at 120 food, is is unwise to risk them far from your town center. They are too valuable to lose them like villagers might be in excursions far from center. But with such formidable cavalry, this faction is slow to get going, and nearly impossible to stop once peaking. Their shipments tend to lean on cavalry improvements and economic benefits, though there are also lots of improvements to native warriors (which is a gamble, because one never really knows if they will get decent ones, per map). But if you can crank food and gold, these guys are tough to beat. Cavalry units just have SO MANY hit points.