What happens if the Dargan emulates a ship with different defense ratings?
Use the ones listed for the Dargan, although this will require deception on the part of the Centauri player. If any to-hit roll would hit the Dargan but not the simulated ship (or hits the simulated ship but would not hit a Dargan), he must reveal his vessel to be a Dargan at that point, and resolve the weapon’s chance to hit against the Dargan’s ratings at and after that point. This makes long-range sniping a good way to pick out a Dargan if the player has selected a simulacrum with radically different defense ratings.