After seeing some footage of naval combat it does seem... silly, to say the least.
I wonder if it could be implemented a tactical map that is basically a Ship Invasion kind of deal. Two ships, hooked to each other, with some planks over for attackers to cross into the other ship.
Could be really interesting, allows devs to play with height (depending on the shape of the ships, but thinking about the ship from DOS2 for instance). Could be a different kind of Siege, where the armies have a shot at playing it more tactically with archers up top and melees down there.
Also if uaing galleys, could add 1-2 cannons to that side.
In my mind, think HoMM3 ship battlemap.