It's also worth bringing up that there is a difference between designing a game and/or character roles around making sure everyone will have fun and participate, and figuring out what to do for a game where vehicle combat isn't something that happens enough to plan character roles around.
@Celebrim brings up some really good points about why squad-based combat works better than other things for group play. What can we do to ameliorate the issues for other sorts of play experiences?
A practical potential solution I hope I can remember to try next time it comes up is to ask the players how they are going to handle it.
"Well everyone, right now Han is flying the ship, Chewie is shooting the gun, and we're probably going to be spending some time on resolving this situation. What are the rest of your characters going to be doing to contribute?"