I played a game this weekend where I had Han Solo flying the Millennium Falcon with Luke Skywalker gunning.
I know there have already posts about this, but when you take into consideration the Falcon's ability to shoot 360 degrees with its Primary Weapon, I think this is broken. Plus, the Falcon's re-rolls intensify it. Basically, Han can shoot twice. If he misses, Luke can shoot--and many say he can use the Falcon's all-dice re-roll, too. So, that's four attacks at 360 degrees, with neat little components like the re-rolls and Luke's Focus ability.
Everyone at the table said this required a rules check; it seemed broken. The Falcon absolutely pummeled the Empire. Four attacks? Four attempts to hit every round? I think it's unfair, and I'm about to establish a house rule that Han use his limitless luck and familiarity with the Millennium Falcon to shoot, re-roll if he wishes, and then shoot again. If he misses on the second shoot, this can activate Luke, who gets one shot. By my house rule, Luke can't use Han's ability. They're separate abilities assigned to A) The Millennium Falcon's pilot B) Luke acting as a gunner on the ship.
I think this all-dice re-roll belongs to Han, not Luke and Han. It's Han's re-roll ability because the Falcon loses it if another pilot (like Lando) is flying it.