It's even better than that.
At least according to the old continuity, the Wookiees were skilled explorers, and their Clatuuvac Guild had the secrets to a number of hyperspace routes, especially through the Core (it's why the Separatists were so keen to take the planet in Revenge of the Sith)... And Chewbacca was one of the people who knew these hyperspace routes.
So the Millennium Falcon being the fastest smuggler ship in the galaxy? About half of that is down to Han's modifications, the fact that he drives like crazy, and the fact that he's almost as good as he thinks he is. The other half? Is just Chewie knowing a bunch of shortcuts, which he got from all the classified information he knew when he was a commander.
Look, if the respected commander wants to bring his rescue human along, so be it. Even if said rescue is poorly socialized.

















