In a fight between DD,the ship that offers the side is at disadvantage because it is fired at 5-6 while has no bonus for beam firing(if it has only 1 AD)
What do you think about a TLW bonus?
The beam shot is only because the ship is presenting a bigger target has nothing to do with the guns. Also Light guns are are considered generic at this scale DDs dont worry about details of my turrets can shoot left or right if you have more than one.
Turret factors dont come into play untill you reach the 6in. guns or better.
Hope this helps