Normally players don't get to do anything for NPCs. But if the players' characters are actually in command of some NPCs, and ordering them to do various things, then it's not too much of a stretch to let the players roll the dice for them. Particularly if the NPC actions are happening right there and there's nothing particularly secret about the outcomes. If the results of the dice roll are going to be known instantly to everyone at the table anyway, there's really no reason for the GM to do them instead of the player who gave the order to the NPC.

Unless you want to hide the roll and fudge the result to turn out exactly the way you want it...

Transcript

GM: Red Ten shoots desperately at the vent grille. Pete, do you want to roll, since you're controlling his X-wing?
R2-D2: This is precisely the situation I have this bag of NPC dice for.
GM: I'll take that as a—
R2-D2: 15!
Red Ten: Bombes loin!
[SFX]: Whoooshh...
[SFX]: Kaboom!
Red Ten: C'est un succès! Arrêter la course de suicide!
C-3PO: "It's a hit!"
Luke: Yeah!
R2-D2: Really? Cool, belay the ramming.
Red Ten: Oh Dieu merci, maintenant je vais revoir ma femme et mes enfants.
C-3PO: "Something something, meatbag concern, something."
Leia: Hey! Watch the language, 3PO.
R2-D2: And translating what she said:
[SFX]: < oofloo oofloo eewoo-ding oofloo >
C-3PO: Ha ha! Good one, Artoo!