What's better for a railgun turret

My two running tests have a massive twin gun turret for a two turret ship that will pierce anything(and it dose quite well at that) or adapting for smaller turrets what house one of each gun but four turrets? Three front two back, the idea is this ship will just destroy ships by riping through them for this I test against the ow just because their ships are rather tough and big so I test pierce and how it dose vs ships that are big enough for the shots to not hit important things