There are a number of 'real life' things that could be used in game to modify the value and characteristics of units:
The big one: make early units either require or have their production enhanced by your type and level of economy/social system. Examples:
1. The number of Slingers you can build is the number of Sheep and Cattle resources you have - because slingers are herd/flock-watchers who use the cheapest possible weapon to defend their charges, and no government of the time actually trained any slingers, just recruited them from the herdsmen.
2. The number os Scouts you can get for free or cheap is the number of Camps you have - each representing a bunch of Hunters who are going to be wandering around the countryside anyway.
3. Warships throughout the game are cheaper for every sea trade route you have - because they represent increasing numbers of trained seamen you can recruit to crew those warships.
And some other features that could be used:
Mercenaries. Not just a civics card, but an actual system for getting Units, either from Military City States, Tribal/Barbarian Camps, or extra-territorial Hiring Fairs. Mercenaries have been such a large part of human civilizations ever since the ancient era, it's a shame that Civ haas largely ignored them until now.
And part of that:
Extra-National Organizations - all the way back to the Classical Era, at least, there were Mercenary ompanies the size of small armies that could be hired, later International Banking Houses, Trade Companies like the Hanseatic League or 'national' trade organizations that acted pretty independently like the Dutch and English East India Companies, modern Cartels and Corporations - even the International red Cross/Red Crescent groups. These could add a whole new set of in-game entities to interact with diplomatically, militarily, or economically. For that matter, many religions had or have now a great deal of 'extra-territoriality' in that they are not confined or limited to any one government or 'Civ' but have considerable cultural, social, and even economic influence on many different political organizations - perhaps another form of Extra-National Organization.
I like this, it make historical sense and is a nice abstraction for the game.
Still I would prefer a more simplified alternative. It is based on the
Classes (social castes) fore very pop-unit. Some examples:
1.
Patorial villages (Pasture improvement) are founded over resources like Sheep, Goats, Cattle and Llamas. Provide train/maintance discount for Slingers.
2.
Forestry villages (Camp improvement) that include resources like Fur, Ivory and Game (Deer, Antelopes, etc.). Provide bonus to Recon unit line.
3. Now
Harbor districts was my first option for these but since they would be needed to build and repair ships it is kind of redundant to link warship bonus to them. So
Fishing villages were a more usefull alternative (despite small fishing boats are not the same as big merchant ships). Of course they are Fishing boat improvement replacement, they would display an area when placing them that allows you to reach marine resources (showing both the village in the shore but also the little ships over the resource).
NOTE: I know there is the option to have Navy Shipyards separated from commercial Ports (also Airfields from civil Airports) but in term of have less but more continuous and usefull distritcs I would prefer to unite them (especially since naval and air gameplay is underused anyway) despite in real history make sense to keep them separated.
- Mercenaries, are a perfect chance to have UU to be hired from "Minor civs" (
Nations for me) but also as Auxiliars when population of the proper
Heritage (ethno cultural) are part of your Empire (even also the heritages from others "Main civs").
- Extra-National Organizations but also
Intra ones could be linked to certains
Ideologies (civics/policies), providing also some special units.
Related are examples I use of the interaction of elements like the ideology
Pastorialism providing
Warrior class denizens (pop units) from your Pastorial Villages (they normaly provide
Labourer denizens), and resources like Horses, Camels and Elephants allowing to train from them the Special Units
Horse Archer,
Camel Rider and
War Elephant repectively. Also others ideologies like
Feudalism providing one
Warrior slot from every Farming, Forestry and Pastorial villages.
Then the idea is to have some representation of the different kinds of people in your population, but still keep it kind of simple with a limited number of classes.
By the way I also would prefer to keep Recon line to be continous from simple "Scouts" to contemporary Special Forces, mostly for simplicity, keep usefull these units through all the game and reduce micro-management.
