If it's just the deathstar's main weapon against the Yamato, I'd agree with you. That being said, there weren't any other limitations put on the battle so I was taking in to consideration the shield the deathstar has, plus the hundreds (if not thousands) of tie-fighters it can unleash. It also has over 15,000 laser batteries for closer defense.
Demolition Man.Joker. Cause I've never seen...Repo Man...? What is that from? Demolition Man? Judge Dredd? Doesn't matter, I've never seen any of them...