Not really needed, but I think it’d be cool to change 3PO’s interaction with the troopers. (“That’s not even a language!”) He should just haplessly be trying to find protocol to attend to, not necessarily aware that the troopers are hostile.
Is it possible isolate the dialogue from any the Clone Wars episodes? There is this scene from The Clone Wars where 3PO is trying to bargain for some fruit. You could dialogue like:
“Excuse me, fine sir, but do you by any chance have Chewie?”
“How much would Chewie cost?”
“May I please purchase Chewie?”
“Very well, 32, but not one credit more!”
I also wonder if he should be so eager to be in a laser battle? He’s not programmed for battle, so it might make more sense for him to be a little uncomfortable with the action.