In much fiction, the heroes will deal with masses of bad guy mooks without batting an eyelid. This is fairly unrealistic, as numerical superiority will often win out against individual skill. So to simulate it in a game, you kind of need special rules to make the mooks less dangerous than they would be if they used the regular person-to-person combat rules.
Many games realise this and have mechanics to handle it. But some games go the other way and combat with masses of mooks will be deadly dangerous to a small group of heroes. In those games, you need a different strategy: avoid such situations using your wits, rather than go in with guns blazing.
Make sure you know which sort of game you're playing.
Commentary by memnarch (who has not seen the movie)
On one hand, good on Chewbacca for trying to avenge Han's death. On the other, I don't see any reason why Chewie couldn't have simply shot before Han got stabbed. That would have been such a Han Solo thing to do! Distracting the target while a friend snipes from far away is like perfect behavior for a rogue that can't hide and sneak attack! And yeah, movie-Han did say he'd prefer a straight fight to all this sneaking around in Episode IV, but then he was perfectly fine with playing bait in Episode VI. This could have been just another extension of that.
In a tabletop game, this would be completely what I'd expect, even with a versus game style thing. In the Mutants and Masterminds system, for example, there's regular characters that the PCs would fall under and then there's "Minion" NPCs that are much, much easier to knock out and are essentially being one-hit wonders. Sidekick characters are special in that while they're meant to be NPCs for the given player, they're also full characters and not Minions. Fortunately, Chewbacca does appear to follow the full character rules as we've seen him get shot relatively recently. It's almost a shame Kylo didn't get hit in the arm to mirror that injury.
GM: Back to Endor. What’s everyone doing?
Chewbacca: Unable to control my rage, I fire at Kylo.
GM: It’s long range. Attack roll at -1.
GM: Sally, Kylo is distracted but you can roll Force Dodge at -2.
Kylo Ren: 6.
GM: You’re hit! Ben, roll hit location and damage.
Chewbacca: Left flank, 13 damage.
GM: That’s a significant Wound. Kylo can walk, but painfully. -3 to all Actions until you’re healed.
GM: Troopers respond by firing at Chewie.
Chewbacca: Return fire!
[SFX]: Pow! Pow! Pow! Pow! Pow!
GM: The troopers’ shots go astray and Chewie takes out four of them in one round.
[SFX]: Pow! Pow!
Kylo Ren: I’m so glad I use the PC rules and not Enemy Mook rules.