The goal here is to sound natural.
That... that's it?
Yep. It doesn't matter what's being said, as long as it flows like a real conversation.
Seems kind of unimportant.
Not at all. For that sense of realism, it's far more important than any amount of accuracy in physics or protocol.
Surely not!
Oh, yes! The audience is people; that is what they know, what they are most familiar with. Some people may know the science behind something, and will go "it doesn't work like that!" when they see the impossible. Some people are familiar with organizations, and will go "you could never get away with that!" when they see a Lieutenant getting orders from a Major. But many will not.
And speech?
Everyone knows what people talk like. For instance, no one says "unimportant" in casual conversation. They'd say it "doesn't matter"
Oh, come on!
I know, it's terrible. We have all these words for things, very precise words, but unless it's a formal speech or written down, people use the same, small common words for everything. Anyway. The audience can accept anything, if the people are still acting like people. It's only when they go "No one would ever talk like THAT!" that you've failed, since everyone knows what people should sound like.
So how's this going so far?
Well, it could be better. Real people interrupt each other, pause in the middle of thoughts, say um and er and that. Honestly, real conversation is like a poorly made engine. Stops, starts, revving up and hiccuping all the time. People's minds are rarely organized enough for smooth dialogue.
