Given that we have no generic Attack Shuttles, I think it's safe to assume that the stat line reflects the modifications specific to the Phantom, whether you assign the title or not. A standard version would probably have at best 2 attack, probably more like 0 and something akin to Anti-pursuit lasers for a small ship. Hera modded the shuttle for her ship to better serve as a weapon for an insurgency.
Good idea! I'm also hoping that the Ghost was heavily modified like the the Falcon. It bothers me somewhat that a freighter can out maneuver TIE Fighters in Rebels. Just doesn't seem right.