Nanban Trade Ships cannot actually destroy anything with their cannons. This item: Total War: Shogun 2 Gold - PC by SEGA Windows Vista / XP / 7 $44.96. Maybe give foreign traders tiny counties with a titular duchy title in places that traditionally opened up to outside trade. I'm also building a few Nanban trade ships so that I can control the sea.
Although each clan is well suited to a specific tactical approach there are some general strategies and tips that should help with any campaign game. Shogun 2 nanban trade ship mod Ai chan Queen of Yuri, Devourer of Traps, Thrusted Witch.