Wouldn't a people with a shortage of iron, not have designed a ship that needs 3000 tons of iron? And the same for a civ lacking tin. I say this as an application of your concepts of technology being driven by environment.
Hit me with pie in the sky, computer-resources-are-no-limitation complexity here. You'd have multiple unit variations in the game, for each kind of situation of abundance and dearth, right?
Or if there was a way to have a unit workshop, but which exported designs with soul, right? Something that, if not the recognized ironclad or first-rate or winged hussar, is something you could love as the creation of your civ.
A case could be made for making Resources constantly available as long as there is any kind of physical connection. To my knowledge there is no evidence of anyone in the pre-Industrial world having any problem getting the resources they needed to make anything, except for a very few, specific instances:
1. masses of heavier 'war horses' in a society where most of the land was being farmed to feed people (China, which as a result was constantly trading with the 'northern barbarians' for good horses)
2. Elephants, which could not be 'grown' in captivity economically, so had to be imported, sometimes at great expense, if you wanted to use them as Weapons.
In this context, Civ's "Resource Limitations" are an artificial game mechanic!
In fact, you could almost say generally that the limitations of resource use were not usually access, but rather were Economic: it just wasn't economically feasible for China to convert masses of land to pasturage for horses if that meant starving masses of people, and there wasn't enough suitable land for both. Bronze was expensive not because nobody could get the ingredients, but because the ingredients (tin, copper) were rarely found in the same place and so one or both had to be imported from far away - and, again, at great expense. In the 19th century, even countries without Industrial quantity Iron deposits built ironclads and pre-dreadnaught battleships (Austria, Italy) - the limitation was not raw materials, but the industrial plant required to make steel, fabricate hulls and guns and engines, and put them all together, which required a huge capital investment in Industrial Base.
This is worth exploring further.
Perhaps a new system for Civ, in which as long as the raw materials are available physically (cross-continent land trade routes, coastal sea trade, inter-continental sea trade, railroad, etc) then in peacetime it is available to everyone within reach, but costs more in Gold the further away it is or the diplomatic status you have with the 'owner' - and 'owner' should definitely include 'barbarian' camps and City States. In wartime, of course, the people you are fighting will stop supplying you, and may be in position to stop trade with a third party who is supplying you, but that represents 'diplomatic status' limitations, doesn't it?
By the Industrial and later eras, there would be an increasing requirement for Resources to keep units supplied and useful (oil, coal, ammunition made from steel and nitre) so there would be increasing pressure to 'Own' the Resources - cue the military actions of the 20th century aimed at securing Resources - Germany's attack on the USSR, Japan's move into Dutch Indonesia and Manchuria - and their ugly consequences.
That could mean reclassifying resources in a new way: into those that can be traded so easily that no government can stop it, like metals and ores by the pounds in the Ancient and Classical and Medieval Eras (100 pounds of iron ore will completely equip a Legionary or warrior and how do you stop every pack animal on the continent?) and those whose movement is harder and therefore more controllable - like 1000s of tons of iron ore for ironclads or 100s of tons of nitre for gunpowder - and therefore requires Diplomatic actions to obtain or setting up your own manufacture and it would be the extraction and manufacture that would become increasingly important. Iron can be hammered into swords in small workshops almost direct from the ores, but steel for a warship requires a steel mill to 'convert' the iron ore, and then specialized mills to forge 300mm gun barrels, boilers, steam engines, and special-alloy armor plate. The Process to the final product becomes as important or more important than the original raw material,