Battleship load outs are not PvP orientated. Its more RP orientated.
You could have the same split load outs in the previous version without the splitting anyway.
So let me ask you, since when have you seen a real life battleship having nothing but flak cannons? Most battleships nowadays house an array of weaponry meant to counter not only other ships but aeroplanes and submarines as well.
Having a split loadout makes more sense than having a battleship with 4 heavy mortars and full battleship prims.