Is PC a PlayerCharacter or PlayerController?
Is a Player(0) directly controls a Pawn?
If yes then this is what you need:
BL_BasicSpaceship -> Blueprint with basic functions of your spaceship, here you have functions for basic movement, shooting and all the common things that all your ships will have
BL_SmallShip -> Inherited from BL_BasicShip on this level you can define how all SmallShips move, shoot etc
BL_BigShip -> Here you can define more complex system of shooting, taking damage, different movement style
Try to build common interface for all your ships to use them no mater which Ship you really control.