Sorry - I wasn't trying to say that's what you said - rather, that's what the data you provided in your post implied. The other thing is, there are no examples, anywhere, that I'm aware of, of forces larger than 39K being sent overseas to fight an overseas war (and even those 39K were going to a rebelling colony were a substantial proportion of the population still supported the British). The sources I provided indicated that sending troops overseas was difficult, and that there were limits because of logistics. In EU4, on the other hand, I've seen Ming sail a fleet from China to the UK (without stopping!) to invade. I've seen France pick up 50K troops and drop them in Borneo to acquire a protectorate (with their closest possession on the Cape). Ignoring the length of voyage issues, because the AI does as well, I'm not suggesting France couldn't have sent a force of, say, 5K effectively, but is France sending 50K troops to Borneo, and being able to maintain itself at full strength in that environment, in the early 1700s, plausible?
The numbers in EUIV are off pretty much all around though. The small garrison states where the vast bulk of the male population took part in local warfare (e.g. Wallachia, Moldovia, etc.) have vastly lower numbers than was historical. Conversely, England maintains a larger standing army in 1500 in game than they managed in real life in 1750. Battles with armies over 100K are obnoxiously uncommon in EUIV. Likewise, defeating RotW powers typically was done with <1K mainline European troops and huge amounts of local mercenaries. France sending 50K to Borneo is less absurd than France not being able to take Borneo with 5K troops.
The most important dynamics for the RotW is that European troops should win often with a low expenditure of resources (compared to a European campaign). The fact that this currently means shipping 50K overseas is less bad than the fact that the cannot do so with historical numbers (e.g. The Aztecs should fall to very minimal numbers, not the 10K or more Spain needs in game).
Historically most states managed to easily send 10% of the main military power on distant operations. Great Britain was unique in that thanks to the strength of the Royal Navy, it was able to send the vast bulk of its forces away from the home country without fear of invasion.
I didn't say the game needed a modern logistics system, but that it would benefit from a better way of measuring the cost of supplying and moving armies, be they overseas or trekking through central Europe. While it is the case that it was easier to supply troops overseas than overland, this still put a strain on the available shipping and required a certain amount of logistical support, usually obtained locally. In EU4, you don't need logistical support - I can literally sail 180K troops from England to China and drop them on the coast and start a siege with no trouble, and these armies are usually about a third artillery. You can then march them over hills, mountains and wherever you like. Warfare in EU4 as it stands is intensely implausible, in a game that, for the most part, revolves around warfare. This is one of the big reasons it's as 'Risk'-like as it is, with big stacks marching around taking all before them. Were the AI able to cope with it, making players have to make the same kinds of strategic decisions in war as actual participants did at the time would add a lot of depth to the game, and improve colonial mechanics at the same time.
1. This is extremely hard on the AI. Logistics belong to a class of problems for which even incomplete solutions are computationally intensive. Currently the naval attrition system consists of a simple straight line distance calculation and a timer; one of the
simplest attrition models. The AI cannot handle it and
ignores it via an AI only cheat.
2. The more realistic the cost of logistics, the rewards of taking territory, etc. the more smart behavior will drive the player and the AI to ship doomstacks to the ends of the earth. The highest ROR for military adventures in the era were things like the conquest of the Aztec and Inca, but even the wars of North America and India proved far more lucrative than taking swathes of Europe. Historically decision makers had no idea how lucrative overseas conquest could be. Given the problem of player knowledge about the real ROR to be had, players make vastly different choices.
In a nutshell, historical leaders had vastly worse information about everything than we have in simple wikipedia articles. Knowing the actual loot to be had taking out India, China, or the Philippines means more shipping of doomstacks not less.
For example, there are some substantial ranges between the east African coast and the rift valley. If the provinces are opened up without some kind of logistics system in place (or supply, or subsistence, or whatever the most appropriate term is), then conquest of the interior would be as easy as you like. On the other hand, if supplying troops over the mountains is a nightmare, it could go a long way to having those nations and provinces in the game, and making it possible for conquest to or fro from there, but also not very likely as it'd be very difficult. Does Portugal want to go inland from Mozambique? Sure, it can, but it's going to bleed manpower to do it, and get little return for it.
The AI is terrible at this though. These are literally some of the hardest types of problems to model when you have humans in the loop, with pure massively instantiated AI you are going to get crap solutions. Like how currently the Ottoman AI will invade over the Sahara to siege useless provinces in central Africa; I'd expect the AI to regularly murder itself trying to expand in the Great Lakes region. You might hard code the AI to avoid crossing those attritionary murder spots ... but then you open up a huge number of tactical exploits.
The truth is even from Kongo there or the East African Swahili states there was extremely little contact with the Great Lakes Region. The game will be less historical if these countries lose their secure rear fronts.
It's true that the colonization system would need some work in order to accommodate the changes I'm requesting. But in all honesty it needs improvement either way. We already have colonial nations and trade companies to represent different types of colonies, and currently each are tied to predefined regions.
As far as mechanical changes are concerned, if you think about it these are really the only two dynamics that need to be reproduced:
Expansion by land into adjacent provinces (Russia into Siberia, colonial nations)
Colonization by sea into coastal provinces (the usual Western European colonizers)
There really aren't too many cases that fall outside these two general dynamics. Therefore, Paradox could really make it so that you can only colonize coastal provinces unless there is a land connection to your capital/your capital is on the same continent (that way Russia can still colonize Siberia and colonial nations can still expand in the Americas). Disable the automatic formation of colonial nations and make it elective. Either form a colonial nation and relinquish direct control or be confined to coastal provinces, it's up to the player.
And to prevent players from forming colonial nations in the wrong places like the interior of Africa, things could still be restricted by region. I think that we can all agree where colonial regions would go (the Americas, South Africa, Australia, and New Zealand). Trade company regions can go pretty much everywhere else- West and East Africa, the Middle East, India, Indochina, China, Indonesia, etc.
It's certainly a radical shift, and I don't think that it's the most likely way that Paradox would accommodate changes to Africa, but I think it's actually quite viable.
A large, large number fall outside of these cases. Most of French North America, for instance, was government directed settlement (on the forts & fur model) that went up the Mississippi & St. Lawrence and was centrally directed. Spanish settlement along the Brazos, Rio Grande, etc. was also centrally directed at times.
Dutch South Africa also settled into the interior with as much state direct as occurred from the coast.
And of course there is Australia which was a penal colony with direct crown control of where settlement was allowed to occur.
The truth is settlement was much less government directed than
anything in EUIV, on the other hand, the resulting colonies were much less independent than any sort of colonial nation.