Let me rock you Chaugnar Faugn
I could go on and on about all the weird retcons people had to do to keep the old canon working at least somewhat, but one particularly interesting trouble regarding the Thrawn trilogy is that it was published concurrently with the Dark Empire comic which was set in the same time period, but Zahn almost completely ignored the events in it because he didn't like it. Which means that the official post-Endor timeline was "the rebels drive the Empire away from Coruscant... But then the Empire somehow re-conquers Coruscant so the rebels have to drive them away a second time."Here are two observations from reading the Thrawn trilogy, the books that really kickstarted the whole expanded universe thing.
- It's interesting how these books strain against the limits of what was canon at the time and how big parts of it are later invalidated by the prequels and the further development of the franchise. Like, it's baffling to me that before Disney reset everything this was all supposed to be one (albeit tiered) canon. The Clone Wars are totally different and even the timeline of when they happened is wrong.
This was common in a whole lot of Expanded Universe material, which usually extrapolated personalities from the characters we see in the movies to fit their whole species. So all Hutts are crime bosses because the one we see in the movie is one, all Rodians are bounty hunters because Greedo was one, etc.
- Thrawn is indeed an effective an interesting villain, but the key to his success is... space racism? He studies the artwork of whatever species he's intending to move against and uses it to determine their fears and how they think so he can effectively plan against them. In general there's an ugly strain of racial determinism in the story. The Bothan general who tries to undermine Akbar can't just be a slimy, politically motivated individual, it is understood that all Bothans are like this.