Late game high numbers of units are VERY historically CORRECT - USSR had about 11 million army after WW2! And read about West-81 USSR military training demonstration! Number of units is limited ONLY by their cost - how much weapons, bullets, food, etc. = money your economy can provide, you can have as many soldiers as your economy can equip & feed! And the more units, the bigger map & more proportional - the more enjoyable & interesting the game becomes, more strategist skills required, and more realistic! The only reason you might NOT like it - if you build too few units & lose to more numerous opponent
But that is NOT a reason to change game to less realistic - the more units, land scales, the more complexity - the more interesting! If it is too hard for you to think that big - you can just select smaller map, but let the large scale options to exist for those who enjoy it! It is easy to scale down, but difficult & very interesting to scale up!
I think most problems you mentioned are NOT that strong really. But
I would argue about some units strength, and suggest to introduce one more mounted horse cavalry unit – Lancers, early light cavalry, recon cavalry, armed with spears / lances / pikes but no heavy armor which differs them from knights. Lancers should have 6 strength and +100% against siege weapons because light cavalry can gallop very fast, faster then knights, thus with less losses pass distance from max shoot range till melee, more of them survive till melee & defeat siege weapons including cannons & artillery easier. Lancers require “Horseback Riding” and “Hunting” techs, and “horses” resource – no metal required. Lancers and Horse Archers when those tech researched, make chariots obsolete (not in parallel but completely obsolete) – that is why Native Americans, Africans, and most civs except most ancient, never ever used chariots, but only horseback riding – chariots were very short period of civilizations, Persians even did NOT use chariots at all but had Immortals riding horse backs, because it is much more maneuverable and efficient (disadvantage of immortal is lack of stirrups compared to lancers), and chariot production should cost almost same hammers as Lancers and a bit more expensive horse archers, maybe even more than each – you have to build whole cart and spears for a chariot, but only a spear / bow & stirrups for Lancers and Horse Archers. Carthagian Numidian Cavalry replace Lancers with additional +50% against melee units, while Mongolian Keshiks replace knights – Mongols never had heavy plate armor due to scarcity of metals, but Keshiks were extremely efficient, like knights – horse archers & lancers are separate units for Mongols. Horse archers were very powerful units very widely used by all civs especially nomadic, no unit should ever replace this most common globally ubiquitous units, from Persians and Mongolians to Native Americans and Africans… Horse Archers used hit-and-run tactics against melee units, evading melee combat because horses are much faster then footmen, thus horse archers must have 7 basic strength and +50% attack against melee units – only attack, as they don’t have this advantage when they are stuck in a city defense, forest, or other tight place. Mounted units are strongest in open fields, cavalry should be king of fields and infantry – king of trenches. Numidian Cavalry are lancers with extra +50% against melee units, and normal +100% against siege weapons. Horse archers are the most Mongolian units ever, Keshiks are heavy cavalry equal to knights, but much cheaper to produce. Knights might be available for production simultaneously with lancers & horse archers, because knights are very strong but very expensive to manufacture, while lancers & horse archers are cheap cavalry, that historically were used simultaneously a lot – knights were nobles while light cavalry were cheaper recruits. War elephants were much stronger units, normally carrying more than one person onboard – they had usually towers on their back with at least 1 spearman and 2 archers in the tower on top of their back, and they must have at least 9 or more basic strength. How a macemen regiment can beat a war elephant regiment, even if there are 2000 macemen and 100 elephants in a regiment? Elephants crushed may times outnumbering Roman Praetorian regiments. Macemen should have 7 strength, its only advantage against a horse archer is in defense in city, forest, hills, or other terrains where macemen don’t have to run long distance under rain of arrows. Elephants must be much stronger then macemen – each War Elephant has many people in tower on top of its back, with several archers and one or more spearmen, long tusks, it is NOT easy to hit an elephant, and even once you hit it – elephant is not going to fall because of just one hit with a mace, it has much stronger bones then a human... Knight should have 11 strength, Cuirassier 13 strength, Cavalry 16 strength. Either Lancers 6 strength + 100% against siege weapons (Lancer is stronger against a machine gun or cannon because it runs faster then heavy knight, siege weapons are awfully mortal at significant distance, but once cavalry reached melee – Lancers & other cavalry can kill siege weapons almost punishlessly in a melee) or Horse Archers 7 strength or both make chariots obsolete not produceable anymore, but Knights might replace only Lancers (or, Lancers still replace Knights with Guilds if no Iron available, or lancers & horse archers & knights produceable simultaneously)) while still allow to produce Horse Archers in parallel, as Horse Arches are very much cheaper to produce then knights, but almost same attack efficiency against melee units – knights only way outperform horse archers against archery units & mounted units. Also, almost any mounted unit from chariots to knights have pike as main primary weapon because who strikes first wins, & sword as secondary after losing a spear stuck in enemy body.
Knights become less efficient from arrows – longbow arrow carry a lot of momentum, and can break bones even if they did not penetrate the plate armor! Crossbowmen were like medieval snipers and should have +50% city attack +1 first strike, while longbowmen should have +25% against crossbowmen +2 first strikes. Melee units were cheap but weak, mounted units were strong but expensive, this lead to the emergence of the nobility class & feudalism formation – the whole purpose of feudalism was to make cavalry pay for their own maintenance.
Also, I would argue about siege weapons concepts – siege weapons are the more efficient the more concentrated the enemy is, but if enemy dissipated in an open field on widest surface surrounding a single canon regiment caught without infantry or cavalry to protect it in open field, or catapults even less efficient – in open field, lets say 100 canons surrounded by 2000 macemen or musketmen, then one shot of canon even with grapes kills 1 enemy, in best case 2-3, compared to dozens killed and wounded from a canon shot in a dense crowd in a city, which is more collapsing buildings also kill and injure or temporarily capture people under ruins even without cannonballs hitting them directly – so, cannons and other siege weapons are extremely efficient when storming a crowded city with very high density of enemy warriors, but very low efficiency in open field if caught by enemy infantry or cavalry without support of your infantry or cavalry – thus, siege weapons must be escorted, and very efficient only in siege, but very weak in other situations. Thus, catapult should have 4 strength +100% on city attack and available with construction because it needs both mathematics and complex construction; trebuchet 3 strength +250% city attack, canon 8 strength +50% city attack +50% against war elephants +25% against knights, artillery 15 strength +50% city attack, mobile artillery 22 strength + 25% city attack.
Musketmen can have 9 strength but +50% against war elephants who have 10 strength.
Also, I see completely misunderstood concepts of modern fleets: missile cruiser has way much wider range then any battleship and can sink a battleship way before it comes close enough to even fire a shot – that is why modern fleets stopped producing battleships, because rockets have way way beyond range compared to barrel artillery! Thus, missile cruiser should have 4 first strikes! Missile cruiser is weaker then WW2 battleship in near combat – if battleship pops out of nowhere near missile cruiser, for example gets out of well defended port or cave right in front of missile cruiser – battleship would probably win. So, missile cruiser might have 38 or 36 strength compared to 40 for battleship. But in reality, missile cruiser will sink a battleship with rockets way before battleship comes close enough to make even a single shot! That is why 4 first strikes – modern naval warfare is mainly about the range, as we can beat any armor – it became more efficient to produce many lighter ships that just carry rockets, then big ships with thick walls, as rockets will sink them anyhow! Missile cruiser will basically sink most WW2 & earlier ships almost flawlessly by 4 first strikes. Only submarines should be immune to first strikes, but no other unit on land, sea, air, etc.! Also, WW2 Submarine can NOT carry nukes – it is too small and there were no nukes at that time, 24 strength earliest Submarine should carry only 1 cargo space of scouts, explorers, missionaries, spies, great people, or maybe on footmen unit without machines (melee, archery, or gunpowder except mechanized infantry – no tank or artillery as they won’t fit it, but USSR transported a lot infantry in WW2 submarines into Sevastopol during its defense) – that is all it can carry, it is like underwater caravel! But WW3 30 strength Attack Submarines – they do carry nukes only, 3 cargo spaces – the authors confused old and modern submarines cargo functions completely, need to do cargo for submarine types vice versa to correct! And also, the Ironclad should look NOT like those ugly malfunctional weak first ever ironclads, but like the famous symbol of the Great October Revolution, the Aurora Cruiser – that is how most steam ships ever produced looked, during WW1! And Drednout type WW2 oil based ships became MUCH stronger because instead of many small canons, they used a few long barrel long range huge caliper cannons with cumulative warheads, which sank enemy ships far away before they even came close enough to fire a shot from their let it be numerous but shorter range canons – modern naval warfare is mainly about maximizing the range, it is about whose missiles reach enemy first, who has longest range wins!
