It's good not to forget your other objectives. In fact, its good to have other objectives, that you can turn to when the first one inevitably goes awry.
In terms of designing adventures for gaming groups, it's good to offer the party multiple objectives. If they have more things to think about than just "explore the dungeon, loot the monsters", then it adds both interest and tension. Sometimes their goals will overlap, sometimes they will be at odds with one another. That's when things become interesting - if they have to decide between slaying the dragon and rescuing the princess because they can only manage to do one of them.
Commentary by memnarch (who has not seen the movie)
Yep; the previous metaphor flew too high to be caught. Admittedly, most metaphors likely would be too high for the stereotypical player unless they could reach up and kneecap a Hobbit. And these ones? I'd have to jump in the same boat of misunderstanding. The only thing I can think of is that there is no way to get to the shield generators, but that they turn off when the Peace Moon is firing. The only way that would make any kind of actual sense to me is if force shields don't care which direction they're blocking against and if repairs are not considered in the slightest.
Ignoring all sensible explanations though, the dramatic timing would work out pretty well here if the shields do turn off when firing. We've got the set-up of preparing for a shot in-comic and what's probably a refueling for a second shot in-movie, we've got Rey on the loose in the Peace Moon and a small strike team coming in for a rescue, and there's the whole Resistance fleet prepped for an attack as well. This could make for an excellent callback to the tense finish of Episode IV if that's what we're leading up to.
Finn: I don’t think your plan is working.
Zeppo: Odd. That’s never happened before.
Chewbacca: We have a second objective. Deactivating the Moon’s defence shield. Perhaps she could assist with that.
General Phasma: Defence is the refuge of those too afraid to be free. White light everywhere but you can’t see a thing.
Finn: You know how to deactivate the shields? Speak, or we shoot!
General Phasma: Such a squeeze; a mad, sad moment.
Finn: There must be a control room somewhere.
General Phasma: Glory to you! Take me there.
Zeppo: Nice to have someone sensible helping us.