That’s correct. But I’d rather have horses and iron visible in the map from the start of the game without needing to research a specific technology. Depending on whether you had access to the resource or not, you should choose research in one or other direction.
Speaking of resources, this is the list of resources I would like to see in Civ VII:
Food resources:
Wheat
Rice
Corn
Soybean
Manioc (aka cassava)
Potatoes
Bananas
Citrus
Cattle
Sheep
Deer
Fish
Shellfish
Whales
Luxury Resources:
Olive oil
Wines
Salt
Sugar
Spices
Cocoa
Coffee
Tea
Tobacco
Incense
Linen
Cotton
Silk
Furs
Dyes
Gold
Silver
Gems
Pearls
Amber
Strategic resources:
Horses
Camel
Elephant (also luxury resource because of ivory)
Copper
Iron
Niter
Coal
Rubber
Oil
Aluminum
Uranium
Other resources:
Hemp
Palm oil
Peat
Clay
Stone
My choice of Food resources is not arbitrary. I chose items with a production of over 100 Megatons worldwide, i.e. items that really impact the economy. Each one is specific of a type of climate and soil.
I will elaborate further on each resource later, but for now I would like to propose a different system for food resources. First, I think that variety of food should have an impact on the health of your population. The more types of crops or animals you have access to, the healthier your population will be and the faster it will grow.
Second, I propose that, once you have access to a crop or an animal, you should be able to specialize tiles on that crop or animal, provided it is under the same climate and type of soil. For instance, potatoes were originally found only in South America but once Europeans had access to it, they started to cultivate it in the old world and enhance the efficiency of the land use by cultivating potatoes in soils or climates where wheat could not be cultivated. However, specializing a tile on a crop or animal could have some setbacks, because if a disease affected the crop or animal, the production of that tile could decrease for a couple of turns, causing starvation. This way, we could solve the issue of the “green plains – food, hills-production dichotomy” that’s being discussed in this topic:
https://forums.civfanatics.com/thre...uction-dichotomy-remain.674049/#post-16183802
First, the old distinction between Luxury, Food and Strategic resources is artificial and too restrictive: I've argued for a long time that Resources should be defined by their use in-game, and that use will vary within the game based on the technology available to exploit the resource.
So, for example, even as basic a "food resource" as Wheat, or Maize or Rice or Potato, are also the basic resources for various Distilled Liquors which are both Luxury Goods and lucrative Trade Items.
Cotton is usually considered a Luxury Resource, but it is also a requirement to produce modern military explosives ("smokeless powder", RDX, etc) and so becomes a Strategic Resource as well in the late Industrial/early Modern Era.
Nitre is an artificial Strategic Resource (because it can be readily manufactured from waste materials in Nitraries) but the nitrates it represents are also a component for crop Fertilizers from the late 19th century on, and so an 'additive' or multiplier to Food Resources.
Second, be careful of using modern statistics to define Resources. There are several food plants that were historically very important that are no longer planted in mass world-wide quantities. Prime examples are Sorghum and Millet: the former the major food crop of many African states, the latter the first food crop of the civilizations of northern and central China. Other early 'regional' important Grains were Barley, Rye, and Oats, none of which are in the top tier of planted crops any more.
In fact, because there were so many 'regional variations' of grains that don't really have separate characteristics in in-game use, I suggest that we adopt the term
Korn - the spelling is German, it was 'corn' in English, though, which will get confused with Maize. Korn simply meant Any Grain, and so can be used to cover Wheat, Millet, Rye, Barley, or Oats, all of which were planted widely and have since been modified to thrive in a variety of terrain/climate combinations - and can all be used to produce Distilled Liquors and so have a similar 'Luxury/Trade' component as well.
Another nomenclature change I'd suggest would be change 'Bananas' to
Tropical Fruit, because there are numerous other fruits native to tropical environments that don't travel and pack and preserve as well as Bananas, and so aren't familiar to European or American audiences, but are important food sources in their 'home ranges'.
A prime distinction that does have to be made among animal resources is between those that can be domesticated and those that have never been. Specifically, the following can be hunted, but have never really been bred in captivity except in modern zoos and so are technically not the subjects of a tech like Animal Domestication or Animal Husbandry:
Elephant
Deer
Walrus (a Major source of Ivory even after regular Whaling was started)
Bison (not just a Big Cow: its leather is much stronger because of its thicker hide, and belts of bison leather to transmit power from stationary steam engines to machinery were a major Industrial Resource in the 19th century)
Whale - the distinction has to be made because Shellfish, Fish and Pearls have all been 'farmed' as far back as the Classical Era (in Rome and China, to name two places) while Whales have never been
Finally, we can debate whether to also include some other very important Domestic Animals:
Water Buffalo
Goat
Pig
I would argue that the Water Buffalo, along with the Yak, are 'regional variations of Cattle' used as basic food animals, secondary (dairy) food animals, and draft animals that don't have to be distinguished: a Cattle resource in a marsh is actually a Water Buffalo. LIkewise, Goats and Sheep are virtually indistinguishable, frequently bred and pastured together, both provide fiber as well as meat and milk (the first Sheep domesticated had no fleece, humans bred them to turn their undercoat into a 'woolly fleece' and it took about 4000 years to accomplish!). Pigs are just too universal and except for their cultural significance (you cannot 'herd' pigs very well, so if you keep pigs you must settle down and are no longer part of any pastoral culture: hence the prohibition against eating or using pigs among pastoral cultures like the Arabs and Hebrews, a prohibition that seems to be earlier than their respective modern religions, and so related to cultural assimilation rather than religious). We can simply assume that anybody settled in one place has both pigs and 'domestic fowl' (chickens, eventually) supplementing their basic Food Crops.