I am curious on the opinion of other players on this. Assuming you are looking for war, and the AIs have dug in enough that bombardment and collateral damage are called for.
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I'm only looking at this time frame. Potential gains from an earlier rush should not feature, but the ability to build your cleanup troop of choice in advance should. Units I found quite useful are:
Quechua: Disposable units to weaken small numbers of healthy archers when catapults would be overkil before you send your real units in. You can keep building them while having access to both Axemen and Spearmen, then upgrade them with conquest cash as needed. Cheaper garrison troops in safe cities, better stack defenders if you are willing to pay for them since they retain the combat promotion when upgrading.
Skirmisher: Cheap and efficient. Knights are the first regular unit to beat them hammer for hammer unlike, say, Muskets or War Elephants. Resourceless so they can be built anywhere. Strong defenders in cities and/or on hills.
War Chariot: Strong general purpose unit on the offense (War Chariot vs. Spearmen isn't any worse than Swordsman vs. Axeman in most cases). Mobile enough to pillage or to get reinforcements to the frontline quickly. Particularly strong against Archers, often more so than Immortals.
Dog Soldier: If our offense relies on catapults, we arguably need quality stack defenders more than we need quality cleanup units. Dog Soldiers provide just that, and we can build them in front cities not yet connected to our trade network.
Vulture: Competent cleanup troops that do well against any defender - Vulture vs. Axeman is usually better for the attacker than Axemen vs. Archer or Swordman vs. Axeman.
Out in the open with no bonuses to the defender, they lose against regular Axes though.
Praetorian: Very strong individually. They can save a tidy amount of hammers that would otherwise be spent on suicide catapults since they can often take cities without much support. Stronger than spearmen against mounted units so Horse Archers flanking our catapults will be less of a problem. They lack a hard counter before Macemen - Axemen lose individually, Crossbowmen lose on a hammer-for-hammer basis.
Hwacha: If we're waging a catapult-driven war, better catapults sound good. Not requiring much in the way of melee defence is especially good if we have access to War Elephants since either covers the other's weakness.
These are the ones I found particularly strong in testing and actual gameplay. I found Horse Archer replacements not worth the wait (any benefit over War Chariots seemed minor considering the difference in hammer cost), and the Bowman, Phalanx, Impi, Holkan, Gallic Warrior and Jaguar Warrior appear underpowered in comparison.
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I'm only looking at this time frame. Potential gains from an earlier rush should not feature, but the ability to build your cleanup troop of choice in advance should. Units I found quite useful are:
Quechua: Disposable units to weaken small numbers of healthy archers when catapults would be overkil before you send your real units in. You can keep building them while having access to both Axemen and Spearmen, then upgrade them with conquest cash as needed. Cheaper garrison troops in safe cities, better stack defenders if you are willing to pay for them since they retain the combat promotion when upgrading.
Skirmisher: Cheap and efficient. Knights are the first regular unit to beat them hammer for hammer unlike, say, Muskets or War Elephants. Resourceless so they can be built anywhere. Strong defenders in cities and/or on hills.
War Chariot: Strong general purpose unit on the offense (War Chariot vs. Spearmen isn't any worse than Swordsman vs. Axeman in most cases). Mobile enough to pillage or to get reinforcements to the frontline quickly. Particularly strong against Archers, often more so than Immortals.
Dog Soldier: If our offense relies on catapults, we arguably need quality stack defenders more than we need quality cleanup units. Dog Soldiers provide just that, and we can build them in front cities not yet connected to our trade network.
Vulture: Competent cleanup troops that do well against any defender - Vulture vs. Axeman is usually better for the attacker than Axemen vs. Archer or Swordman vs. Axeman.
Out in the open with no bonuses to the defender, they lose against regular Axes though.
Praetorian: Very strong individually. They can save a tidy amount of hammers that would otherwise be spent on suicide catapults since they can often take cities without much support. Stronger than spearmen against mounted units so Horse Archers flanking our catapults will be less of a problem. They lack a hard counter before Macemen - Axemen lose individually, Crossbowmen lose on a hammer-for-hammer basis.
Hwacha: If we're waging a catapult-driven war, better catapults sound good. Not requiring much in the way of melee defence is especially good if we have access to War Elephants since either covers the other's weakness.
These are the ones I found particularly strong in testing and actual gameplay. I found Horse Archer replacements not worth the wait (any benefit over War Chariots seemed minor considering the difference in hammer cost), and the Bowman, Phalanx, Impi, Holkan, Gallic Warrior and Jaguar Warrior appear underpowered in comparison.