My though t is this…Have turret bonuses affect weapons below their size by default. For example, a battleship that gets bonuses to Large Turrets, Those same bonuses would automatically apply to Medium and Small Turrets. For Cruisers and Battle Cruisers, their bonus that affect Medium Turrets would also apply to Smalls. Frigs and Destroyers would not be affected, since they only have small turrets.
This would allow for more flexibility and layered ranges. You could even add more turret hard points to the ship hulls, without unbalancing too much, as long as the PG and CPU stay the same (or change very slightly)