Army Commanders in Civilization VII (Civ 7) represent a significant new feature in the game's combat system, designed to streamline unit management while adding depth to military strategy. Here's a comprehensive look at how Army Commanders work in Civ 7:
Overview:
•Introduction: Army Commanders are introduced in the Antiquity Age and are pivotal for military operations in Civ 7. They act as a central figure for your army, providing numerous strategic advantages.
Functionality:
•Unit Stacking: Commanders can stack up to six units onto their tile, allowing for easy movement of large armies across the map. This reduces micromanagement by letting you move multiple units as one.
•Experience and Promotions: Unlike regular units, Commanders are the only units that can gain experience and earn promotions. They level up by having units under their command engage in combat, unlocking various bonuses and abilities from five different promotion trees: Bastion, Assault, Logistics, Maneuver, and Leadership.
•Age Retention: Commanders retain their experience and promotions across different eras, making them invaluable assets as the game progresses.
Key Abilities:
•Focus Fire: Commanders can coordinate ranged units within their command radius to focus their attacks on a single target, providing a +2 combat strength bonus.
•Coordinated Attack: They can also lead infantry and cavalry in a coordinated assault, again boosting combat effectiveness.
•Reinforce: Commanders can call for reinforcements, which automatically bring units from your empire to their location, significantly reducing the need for manual unit movement.
Strategic Implications: 
•Reduced Micromanagement: By grouping units under a Commander, players can manage large armies more efficiently, making warfare less tedious and more strategic.
•Tactical Flexibility: Commanders allow for quick redeployment of forces, enabling players to respond to threats or opportunities swiftly across the map.
•Strategic Upgrades: The promotion system for Commanders adds a layer of strategy where players must decide how to specialize their commanders, whether for defense, offense, movement, or city support.
•Civilization Uniques: Some civilizations have unique Army Commanders with special abilities. For instance, Rome's Legatus can found new settlements upon gaining certain promotions.
Gameplay Considerations: 
•Protecting Commanders: Since they carry all the promotions and experience, losing a Commander can be a significant setback. Players need to balance the risk of deploying them near the front lines with the benefits they provide.
•Tactics and Terrain: With Commanders, terrain and unit placement become more critical. Utilizing the maneuverability and bonuses provided by Commanders can turn battles in your favor, especially when considering flanking or fortification.
•Commander Types: Besides Army Commanders, there are also Fleet Commanders for naval units and Squadron Commanders for air units, each with their own promotion trees and abilities as you progress through the Ages.
Community Reception:
Based on posts found on X and various guides, the introduction of Commanders has been seen as a "game-changer" by some, offering more strategic depth to combat while others have expressed concerns about the loss of individual unit promotions.
In summary, Army Commanders in Civilization VII are a central element of the revamped combat system, intended to make warfare more dynamic, strategic, and less about micromanagement. Their use will be crucial in achieving military victories or defending against threats, adapting to the new mechanics of the game where experience and strategic placement play a larger role.