Total War: SHOGUN 2

Total War: SHOGUN 2

Ultimate Expanded Field Command V1.58
Naval Battle and sinking ships
Hi, is it normal or not that a portuguese Galleon can't sink any ship,even a simple wako trade ship that survived 40 cannon shot from my galleon.

The only way to win is to make them surrender/flee, but if i only want to sink them and not capture any of their ship to not have to pay or have to manually disband their ship after the battle; fire arrow is superior to any naval weapon in general as once the ship is on fire the AI will stop everything on the ship to try to put out the fire and let my ship continuously loose fire arrow at them as the timer to the fire arrow capabilities is low enough to make sure the ship stay always on fire and then burn down.

Is there anyway to make at least canons on galleon able to sink any ship at all without having to relly only on the ennemy fleeing or surrendering.