Hi Weierstrass. It was been a pleasure playing your mod and i think it is important to give you feedback.
I build one nanban caravel and took it to battle. Well the problem is that the nanban caravel is not a caravel. In fact is just another carrack but not a portuguese carrack which is also strange but i will come to that later. The funny thing is that i am portuguese and i live in Brazil and the brazilians also call the portuguese carracks , caravels but this is a mistake.
https://en.wikipedia.org/wiki/Caravel
Where you can see the 3 different types of caravel build by the portuguese.
https://en.wikipedia.org/wiki/Carrack
And here you can compare with the carracks to see the diferences.
Now i am saying is not a portuguese because it haves 3 square sails in the 2 main masts. Portugal build the carracks with 2 square sails instead of 3.
Anyway apart from the mistake in the name i want to mention that "nanban caravel" with 10 guns have an 671 upkeep when the nanban carrack with 24 guns only haves 447 upkeep. So maybe you could invert the values or tweak them?
I would also like to mention that the archers ashigaru should have a little nerf in the attack values. The way they are now unless they are going to fight cavalry there is no reason recruit yari or naginata ashigaru. So a little nerf to the attack value in the archers ashigaru or a little buff to the attack values in the yari and naginata ashigaru to keep things interesting.