The only way you can really win is using the fire arrows concentrated on a ship or the guns so keep these boats moving always and always engage as soon as possible these ships while the rest can make you get a bit more time. imagine its extremely left and a bit to the front, just pull them hard right while still moving foward and then you can change the direction of the ship to take advantage of the wind) You have to learn how to use the wind which is really simple, just make the boat follow the yellow arrow and if the wind is not where you want to be just reposicione your boat (ex.
Your navy should have this structure since is the most effective if you are not going with a navy as the one mencioned : - 4 bows/guns(anti everything) 2 sengoku bune(anti bows) 4 medium/heavy bune(keep the same ships and sengoku bune busy) To fight the Al naval spam just have a navy full of bows (fire arrows)/gun boats, its an exploit but its just a nonsence the continuos spam the Al does. Most of people hate the vanilla naval battles but if you master it or know how to fight the Al spam you will actually enjoy a lot like myself.