I just bought a complete set of Shogun 2 and played small naval battle to familiarize myself with the interface etc. My fleet consisted of two ships: Medium Bune and O Ataka Bune, the enemy ships Heavy Bune and Sengoku Bune. The problem is how enemy ships behave. The enemy moving into the wind. What surprised me is the lack of paddles in both the enemy ships. Although Sengoku Bune has a sail but then he drifted into the wind and the sail was not set (but ship swam fast). On the other hand I do not understand how Heavy Bune moving which has neither oars nor sails. What this is about?