Siege is the Ethiopians' strong suit, as they are the first and only civilization to have access to every available Siege Workshop units and upgrades and their unique technology, Torsion Engines strongly benefits most of their siege devices.
The basic Ethiopian rank-and-file are not bad, either. Their Spearmen receive instant upgrades to Pikemen and Halberdiers for free upon reaching the appropriate ages, so cavalry will not be a major concern in most engagements for Ethiopian players; Ethiopian Archers fire 15% faster than those of other civilizations and their Blacksmith has much if not all of the necessary upgrades towards a strong Archer-based frontline. The Ethiopian's unique Shotel Warriors are blessed with a very short deployment rate (even more rapid with Royal Heirs) for a very cheap price, allowing tactful players to overwhelm their enemies with sheer number if they build their Castles close to the battlefield. Players on a team with Ethiopians will receive a +3 boost to their Outposts' and Towers' line of sights that can provide a security advantage in the early game.
While Ethiopians have access to nearly every available cavalry types in the game, they do lack Bloodlines and Plate Barding Armor for conventional Stable units and Parthian Tactics for Cavalry Archers, meaning their mounted troops will not last very long in a scuffle unless backed up by Archers and/or Monks. Their Militia line is also not very effective in the late game due to the lack of a Champion upgrade. Because of this, their only reliable frontlines are Arbalests, Halberdiers and Shotel Warriors, all of which can be countered fairly easily even by Huskarls.
The Ethiopians have a very weak Dark Age as they do not have any significant economic bonuses across from the free 100 food and gold when aging up. As such, the player should focus on booming their economy and play defensively against civilizations with early aggression such as the Aztecs, Huns, Mongols, or Malians. Upon reaching the Feudal Age, Ethiopians players should consider training masses of Spearmen to discourage early game Scout Cavalry aggression and Archers to counter Men-at-Arms rushes (although the Ethiopians are still vulnerable to Archer and Skirmisher rush aggression like the Mayans or the Britons, the Spearmen and Archers will have a lot of value due to the Ethiopians free upgrade on their Spearman line and the Archer faster firing rate). Defensive Watch Towers should be considered to discourage any early game aggression from the enemy thanks to the line of sight bonus. Offensively at early game, making an Archer rush during Feudal Age is a viable tactic for Ethiopians, and Tower rushing is also effective due to the expanded LoS. Monk or Pikemen rushing is also effective if the player can exploit the bonus resources per age/has a strong Feudal economy and manage to reach the Castle Age before their opponents (see below).
Making a mad dash towards Castle Age as an Ethiopian player is very possible, though it may require one to temporarily ignore Loom during the earlier ages to amass enough gold to upgrade (just the 100 initial gold plus the 100 more received at the start of Feudal Age is enough to research Castle), which may leave their Villagers vulnerable towards wild animals or if an opponent decides to commence an early raid. The recommended focus during Feudal Age should be on gathering food for the upgrade and wood for the requisite Market and Blacksmith. This rushing tactic allows the player to advance in age very rapidly if workers are properly micromanaged, but will leave their economy lopsided and vulnerable if they aren't quick enough to adapt. If properly performed, this fast-Castle technique will allow the Ethiopian player to pull off an early Monk or Pikemen rush, the latter of which is recommended since their Spearmen line is upgraded automatically upon aging up for no additional cost, and is very effective against very much anything an opponent can muster up during the early game if deployed in mobs.
During Castle Age, the player should consider rushing a Castle in their town and research Royal Heirs and Arson. Once the castle is built, Ethiopian players not only have a Castle to defend their town, but they can now create mobs of Shotel Warriors almost instantly to help quickly defend their town against raiders. At this point they can begin to consider raiding nearby enemy colonies with their upgraded Shotel Warriors, Archers and Pikemen. Thanks to the Shotel Warriors and Royal Heirs Ethiopians can also perform a Castle drop tactic against an enemy town more effectively than many other civilizations.
Much of the Ethiopian's lategame is not from their instant spawning Shotel Warrior, rather, their lategame power comes from their wide variety of siege weapons. With the Ethiopians being the only civilization having access to every upgrade for their siege weapons, combined with the larger blast radius from Torsion Engines, their siege weaponry, combined with their cannon fodder of free upgrades with their Halberdiers and faster firing Arbalest as their backup support, makes the Ethiopians having the most threatening and deadliest army compositions lategame without the need of cavalry (since their cavalry is incredibly weak due to lacking Bloodlines, Plate Barding Armor, and the Paladin upgrade). Any left over Shotel Warrior from Castle Age raiding (as well as any Shotel Warriors created) should be garrisoned in Siege Rams to help the Rams get close to enemy buildings (as well as helping the Shotel Warrior's weakness towards arrow fire due to the Siege Ram's high pierce armor). Siege Onager and Elite Skirmishers should be mixed in with Arbalests to counter enemy Archers and cavalry archers, and the Halberdiers should be the Ethiopian's main frontline to protect any cavalry charges from the enemy that would destroy their siege weapons and Arbalests. Bombard Cannons will be very threatening to enemy defenses and siege weapons thanks to the larger blast radius from Torsion Engines. Players should consider building forward Barracks, Siege Workshops, and Archery Ranges and overwhelm the enemy with cheap cannon fodder with Shotel Warriors and Halberdiers as their main frontline with siege weapons and faster firing Arbalests as their backline support.
The Ethiopians are great against civilizations with weaker archery lines (i.e. Vikings, Slavs, and Spanish) and are a threat to civilizations that depend on cavalry during the Castle Age and lategame (i.e. Huns, Persians, and Berbers) due to their free upgrades for their Spearmen line, thus dissuading Castle Age Knight rushes. The Ethiopians will struggle against civilizations with stronger infantry lines (i.e. Malians, Teutons, and Japanese, and Aztecs) since the Ethiopian's only reliable anti-infantry option is the Arbalest and their Shotel Warriors and Halberdiers will get shredded by the said civilization's stronger infantry since the Ethiopians lack the Champion upgrade. Byzantines can devastate the Ethiopian army since the Cataphracts will destroy their Halberdiers, Shotel Warriors, and siege weapons while their cheaper Skirmishers will make quick work on the Ethiopian archers. The Goths can destroy the Ethiopians lategame, as the Ethiopians have no cost effective answer to their cheap infantry spamming and can easily overwhelm their siege weapons (the Huskarl unit can 1v1 a Shotel Warrior and is more cost efficient than a Shotel Warrior, and the Huskarl unit can easily shred their Halberdiers and Arbalests). The Ethiopians will also struggle against the Mesoamerican civilizations, since the free Spearman line upgrades will be incredibly useless since the Mesoamerican civilizations cannot build cavalry and the said civilizations have appropriate answers to their army composition (Elite Eagle Warriors can destroy their siege weapons and Arbalests, while Aztec Jaguar Warriors, Mayan Plumed Archers, and the Incas Slingers will make quick work on the Ethiopian Shotel Warriors and Halberdiers).
Ethiopians synergize well with many other civilizations. Allying with the Koreans is considered to be the best bet, as they will benefit from the Korean team bonus of reduced minimum range for their Siege Onagers in addition to Torsion Engines (and vice versa for the Koreans with the Ethiopians line of sight bonus for their towers). Teutons are also good allies to the Ethiopians since they can garrison additional units in the latter's towers and the Teutonic team bonus makes Shotel Warriors difficult to convert. The Slavs are recommended for aggressive players as their population room bonus can be exploited by building many forward military facilities. Allying with the Italians will supplement the their already weak frontline with Condottieri, which is a good alternative to the Champions that the Ethiopians sorely lack, while also providing stronger anti-gunpowder unit support. Allying with any archer-based civilizations with archer team bonuses such as the Britons, Magyars, and Saracens makes their Arbalests more devastating. Allying with the Goths is very beneficial as it allows the Ethiopians to build Halberdiers faster and supplement each other's weaknesses (Goths have a very strong frontline, but a weaker siege line and Ethiopians fare the other way around). Allying with Celtic players can benefit an Ethiopian's siege industry with a handy creation speed boost. Lastly, allying with the Berbers is also a no brainer considering the team-benefiting Kasbah technology, which will increase the training speed of Castle units and, when stacked with Royal Heirs, can make Shotel Warriors extremely effective with the Castle Drop tactic.
The versatility of the Ethiopians in team games allows to them to play supportively, defensively or more aggressively than in free for all games. They also are great at Springboard tactics if playing with them as the Springs since most of their bonuses shine at Castle age and early Imperial age.
Since Rise of the Rajas, all Southeast Asian allies offer Battle Elephants as meatshields to screen Ethiopian foot units and siege weapons. Amongst them, Khmer allies deliver range boost to the Ethiopian Scorpions with Siege Engineers and Torsion Engines upgrades, plus supporting hand cannoneers; while Vietnamese allies offer bankroll for extra Ethiopian siege weapons by Paper Money and Imperial Skirmishers, in exchange for far-sighted Keeps and firepower support from Ethiopian siege units' suppressing fusillades. Malay and Burmese allies are also competent teammates for Ethiopian players, for the former grant them far-sighted Docks as a vital component of a fast-response fleet needs, while the latter reveal and share locations of the relics at the beginning, allowing them to amass spearmen and foot archers to secure nearby relics early-game for future gold supplies.