There is a non-trivial difference between "difficult" and "random". Being insta-gibbed by the nooby CB (aka colonial conquest) will put you in situations where your soldiers can't win battles. It's a situation where Mesoamerica is denied ships because it's "ahistorical" but it's still okay for Europeans to ship 25000 soldiers to the new world before 1550.
Potential solution: Mesoamericans are still denied boats, but the attrition penalties for
troops on transport ships crossing the open ocean are massively increased (slowly decreasing as DIP tech increases and then removed at DIP 22, just like the removal of the "time at sea" penalty for ships themselves at 22), while reinforcement rates for armies in "primitive" provinces in North and South America that belong to a nation whose capital is not in North or South America are also significantly reduced.
That way, CNs can still take on natives without suffering severe reinforcement penalties, because the terrain they're facing is also terrain that they're becoming accustomed to. On the other hand, Castile and Portugal can still
try shipping 25,000 men to Mesoamerica, but until the 17th century (-ish) they will have vastly less than 25,000 men when they arrive. (I'd hope that, ultimately, it would be impossible to end up with more than a few thousand men from Iberia actually landing in Mesoamerica in the 15th century, regardless of how many set out.)
The game becomes more historical (Mesoamericans lose their magic heavy ships, but Europeans actually have to care about logistics), but not at the expense of gameplay - Mesoamericans now have a fighting chance at winning wars against Europeans on land pre-Westernisation, while a Euro player now actually has to think about how they're going to approach Mesoamerica, rather than just boringly ROFLstomping everything with 25,000 Magic Scurvy-Proof European
Uebermenschen in 1500.
As a corollary, I'd also remove the "New World provinces don't give nationalism", which is easily the worse change in the 1.10 patch-notes. Teach CNs and subjects in general to core (I feel your pain on this, TMIT, I really do), and I reckon that my proposal might lead (with some balancing of the attrition on transported troops, but that'd be Paradox's job, not mine) to more historical*
and more interesting gameplay between the Old World and the New.
*(well, mostly, but I don't think that allowing the Iberians to ally with other Mesoamericans mid-war and call them in would be good for game-balance)
. Serious messing with subject nations and liberty desire absent a fix to a longstanding, frustrating, and game-altering bug would come off as pretty sour. All in all most of the changes look good otherwise.
