Personally, I think that this debate over the relative importance of Europe to China/India/Japan and China/India/Japan to Europe is a bit unprincipled because it misses one incredibly important fact: economies are/were interdependent (yes, even at the time). Europe during EU4's time frame began conquering the New World and undergoing some critical processes that enabled European imperialist domination of the globe during Victoria's time frame, but China and India were actually influencing those directions and possibilities.
To explain, some European nations were dynamic and beginning to explore new modes of economic life (capitalism and the formation of corporations, first wave British industrialization, etc.), but one of the major drives for these changes was a desire for Chinese and Indian luxury goods (tea, Chinaware, silk, and spices). Generally speaking, European medieval economies weren't that different from what we see in China, Japan, Korea, the Muslim world, etc. Standards of living, life expectancy, and tons of other indices of quality of life - as well as patterns of economic behavior - were basically equivalent in any of these places. It's commonly known that the Portuguese and Spanish embarked on exploration in the New World and the African coast out of a desire for East/South Asian goods, but I'm less certain that wide swaths of people generally are aware that Spanish (and later British) desire for silver from the New World was encouraged by the fact that European traders, mercantile companies, and monarchies wanted goods from the extended Chinese market but had limited buying power for them because China only accepted silver as a currency. European nations were largely reliant upon gold backing for their currencies, and as they didn't find much gold but found relatively large amounts of silver, a significant measure of European profitability from New World ventures came from European-Chinese trade.
In other words, not only did the East/South Asian economy encourage Europeans to find and explore the New World, it made the conquest of places like Mexico and Peru economically advantageous to European nations in a way that otherwise wouldn't have been immediately the case. These economic impulses did not end during EU4's period either, encouraging British expansion into China during the Opium Wars, plus British incursion into Afghanistan (for opium) and India (in part to start tea plantations) as a way of establishing an opium-tea-silver triangular trade to circumvent Chinese trade policies/barriers. A critical side effect of European expansion into the New World to obtain Chinese and Indian goods was the introduction of products like sugar cane, coffee, corn, spices, and potatoes into the European economy (at least in forms or volumes not before easily obtainable), which then facilitated urbanization, capital accumulation, and industrialization in Western Europe, allowing some European nations to break free from the mold (or what historian Kenneth Pomeranz dubbed "economic cul-de-sacs") characterizing pre-industrial economies.
Note that I'm speaking somewhat in generalities here because we're discussing several nations over centuries of time. Also, obviously, European colonial expansion in the New World (and some places in Africa) included an essential ideological (largely religious) component that I don't wish to deny. Btw, I'm basing my perspective here on books like Kenneth Pomeranz's "The Great Divergence" and Sidney Mintz's "Sweetness and Power: The Place of Sugar in World History."
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TL;DR version: Let's please get away from (IMHO unproductive) claims of either Europe or China being more important during EU4's time frame because they were not acting in a vacuum. Europe was starting to do new and important things in the global economy and the conquest of the New World but China and India were helping influence these possibilities. Our world would probably look a whole hell of a lot different if Europe from 1444-1820 didn't exist or was radically different, as it would if China from 1444-1820 didn't exist or was magically different.