I think that in the future when we stop spending money on stupid things like the Space telescopes and spend them on Space Battleships instead that these space Battleships will probably handle quite similarly to Water Battleships. I think that having centreline main guns will still be quite important for the same reason they are on the water and I think they will still have an armoured citadel of a similar type to water Battleships too. In space you could technically rotate your ship so that you presented you deck to the adversary and thus opened up your guns more but your deck is less armoured and will be much broader for reasons I will go into so that would be a bad idea, ships would still try to stay level with each other almost as if they are on water. Maybe they could try to angle a bit but depending on layout and such that could do more harm than good. I think the difference would be the height of the ship itself. A battleship is actually fairly tall but most of her is underwater so her armoured belt is actually quite narrow, it only needs to go down a bit under the water line. There is no water line in space so they would have to armour the whole side, however, as they are not travelling through water hydrodynamics does not play a role so the ship does not have to be narrow across the beam and can be as wide as she likes so I think space ships will end up looking like what a battleship looks like from above the waterline and upwards but much wider when viewed from above.