As some have correctly stated, flight archery (shooting upwards) was not that common, the arrow loses too much energy from air friction. For the same reason, archers wouldn’t shoot at maximum range, but at around one third of it, which means shooting straight at the enemy from a close distance (also to greately increase accuracy). Thus, the reason for missiles historically not dominating is not friendly ”fire”, although that puts constraints and I agree it should be included. The main reason is that one runs out of missiles incredibly fast. An archer can shoot around 10 arrows per minute, and can carry up to around 70 arrows (a horse archer around half that). They are done fast but in over 7 minutes because the pace cannot be kept. They need to be resupplied, like the 10000 Parthian horse archers were at Carrhae by camels, which allowed them to shoot around 2 million arrows on the Romans. Imagine the volume all that would have taken.  It’s all about logistics. This is one of the main advantages firearms had when they appeared: lead balls are small and easy to transport (let alone easier to produce). Shooting was slower but more efficient, and required less training. Friendly fire was not a big concern.   Someone proposed somewhere for ranged units having limited ammo and going back to replenish. He was closer in pinpointing the issue with ranged units, although that is not how things were done in antiquity. A baggage train would follow the army, which could be resupplied from local resources (trading, plundering, living off the land) or, in case of long term campaigns, supply lines from one’s territory. Supply depots would store supplies. Earth 2150 implemented resupplying amazingly, a building would produce automated flying units to distribute munitions to whoever needed them. No micro. One just has to keep supply lines open. For 0 A.D., a clumsy Baggage Train unit could accompany the army to resupply what’s needed (arrows for now). I think Rise of Nations had one for attrition reduction bonus when outside one’s territory. I have ideas on how to make this even more realistic, using what the game already has, but don’t want to turn this into a “supplies” discussion, unless asked.

I thought about rebellion considering the Carthaginian Mercenary Wars, but wanted to keep it simple for now, maybe the basic ideas has to first be tested. And that should happen if you run out of metal while the contract is on. Bribery would be interesting, but troops under Hannibal should cost a fortune for example. I forgot to say that the cooldown countdown should start after the battalion returns to their closest camp (called Embassy in the game now I remember, but sounds too formal for me, Iberian Camp would be nicer for the context), otherwise they might be instantly available after the contract is finished, which is not the idea. They need to replenish, rest, spend their hard earned money...

Sounds inteersting - we might also consider that - if you stop paying your mercs - they may turn hostile against you, join your adversary or at least revert to gaia "raiders"? The bribery mechanics could also be used to convert mercs to the other side. Not sure if this turns out to be too complex micro-managing for gameplay.

second try vs AIx4.. Good luck trying to recognize the building fast!  And yeah, interesting Wonder ...

I wonder if completely changing the mercenary system can be considered, right now not much differentiates them from regular units, making them boring. I know they are cheaper in general, expensive with metal, and more experienced, but the Carthaginians seem just overcrowded with similar options, which doesn't make them interesting enough. I think mercenaries should aim at being used by those who have the metal but not the kind of unit, population or time to put in place an army. I don’t know if any of the following can even be done (or if it breaks gameplay somehow): I would make mercenary camps produce units in fixed battalions, fast, with a cooldown, and counting for less population, maybe half. Besides one having to pay a certain amount to hire them, they would charge per certain amount of time as long as they are hired. One can cancel this contract any time, after which they would automatically return to the closest camp of the same type (building a disposable raft if needed, I guess, or they could just vanish on some shore if too much extra art is required for now). The cooldown is always a base time plus a time that depends on their losses, to imagine they have to replenish their forces and avoid spamming them if they are getting destroyed, which would be annoying for the other player. This way one should strategically alternate between all camps, like the Carthaginians should. The only variables needed are size of battalion, population cost per mercenary, metal upfront and rate, and base plus penalty cooldowns, which need to be decided for balance, and maybe modified with techs and auras (considering Hannibal was an inspiring figure for regulars and mercenaries alike).