I think it is a great idea to have the sea battle aspect of the game. There is already soldier on the ship for example like 80 mens and it is those unit who will be doing battle; so if a whole fleet is around 1k men then it will be a big battle just like the land one. What they can do is that make it like land battle start with a zoom in and then the pre battle speech. After that showing ship sailing just like a whole unit moving and then when it get close enought to the enemy fleet, both side men jump aboard the ship and fight just like a battle in the wall.