When it comes to rules lawyering, being technically right is far superior to being merely conventionally right. Being right according to the spirit of the rules is all well and good, but nothing can touch you when you're right according to the letter of the rules.
[Reminder: Our guest commentators have not seen Rogue One. Part of the fun is seeing how their untainted impressions re-interpret the movie through the lens of our comic.]
Let this be a lesson to all GMs out there: think very carefully about every rule you make. The PCs will either exploit it, or dedicate themselves to working around it. If you aren't okay with both happening, just don't bother with the rule.
In this case, Pete saw the rule as a challenge. So he found a way to work around it, much to his satisfaction.
Jim on the other hand, is exploiting it (but without the deliberate thought that most players would put towards such a task). He's using the rule to get away with splitting the party, and getting to have two separate adventures.
The GM was clearly okay with Pete's reaction to the rule, because he saw Pete having fun, and it wasn't that bad for the GM to work with him having a familiar like Baze.
Jim's reaction sadly means more work for the GM. Twice the work in fact. Maybe more because he'll probably need to flesh out Bail's party with more NPCs.
If he had just kept his mouth shut about that rule though, he could have avoided it all.
So you're going to split the party before you even get started?!
You're going to run both at the same time, and you're probably both going to die at the same time.
Well, they never said it was one per session. Just that it was four in four sessions.
Have I managed to predict anything in this movie correctly yet?
Bria: Wow, Bail, you are so cool and edgy.
Bail Organa: Yeah! I am.
Bria: Will you join our party?
GM: You can't play two PCs in the one party.
Chirrut: That's completely different! Baze is my familiar!
GM: ... Technically he's right.
Chirrut: The best sort of right.
Bail Organa: Okay, cool, we'll split up and do two missions!