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.
