No thats not the issue. The most unhistorical feature in this game is that Europe can colonize the New World before they can even get to Asia. Its not a theory, debate or fantasy it is fact that they had footholds in Africa and Asia before Portugal even settled in Brazil. Yes they discovered the New World earlier, but nobody colonized it for decades after. Ship range and colonial range should be changed increasing the range to the New World for colonizing and shortening it to Africa.
True, that. In my opinion...
- "Open waters" attrition needs to be even deadlier relative to "time at sea" attrition (or ships could be able to dock in uncolonized provinces to reset time at sea without repairing). Crossing the Atlantic should be significantly more difficult than hugging the African coastline, rounding the Cape, and discovering Asia.
- A Treaty of Torsedillas style mechanic would incentivize Asian expansion. Or an Inter caetera style mechanic (e.g. the papal controller can claim all provinces in a certain colonial region / trade company charter, or perhaps any nation could spend papal influence to do the same).
- Europeans should be able to somehow gain cores on overseas conquests -- Portugal had a "core" on Goa in the sense that Goa became the focal point of Portugal's Asian operations, as early as 1510. Something like a mechanic whereby any country can designate one overseas province its overseas capital for a free core on that province.