I wasn't familiar with Saw when I first watched Rogue One, and I thought the movie provided more than enough information for the purpose he served in it - leader of an anti-Imperial faction, formerly part of the Rebel Alliance, but disavowed due to using extremist methods. Nothing about his history is brought up in the movie, so knowing more about him is simply a nice bonus - it doesn't fill in any gaps in his portrayal.
I think that is very intentional in this modern era. When your always looking for new content to make, leave things vague gives you the ability to make content to fill in the gaps later
They really should have avoided the accents for the Gungans, tightened up the pod race, and taking things a tad more seriously, then it would have been a lot better in hindsight. It's one of the rare Star Wars movies with an actual plot and not just "random things happen in a sequence". And making a kids movie about a trade embargo is such a wild idea that I have to defend the movie on that alone.
Gonna disagree on that. We first meet him in a shady bar in a wretched hive of scum and villainy. He shoots Greedo under the table. Crime boss is leaning on him. Smuggler cargo cubbies that pass initial inspection by imperials. Everything says he‘s a reasonably dangerous and seasoned smuggler. And it’s not until he’s packing up his reward on Yavin’s moon that we have any hint of him having second thoughts about the connections he’s building.
It's hard to tell in the films themselves, but by canon, Han spends three years with the Rebel Alliance in between episode 4 and 5. Something about the Rebellion struck a chord within him. Chewie probably had some input on the matter too -- the Empire was not kind to the Wookiees.
