I think the New EU should have taken more inspiration from the Old EU the same way the MCU “adapts” their comics. Not a direct copy, but taking the best pieces of certain stories and mashing them together.

I love the idea of an extra-galactic “invading force” being the antagonists, so I’d take the main conflict of the New Jedi Order books, though perhaps instead of the Vong it could be the Sith Race from SWTOR or an entirely new species.
I would make Ben Solo a Jedi to begin the trilogy, and have his turn mirror Jacen Solo’s somewhat. He first turns because he believes the Sith are a necessary evil to combat the Vong. He’s put off by Luke and the other Jedi’s defensive-minded tactics and thinks they need to go on the offensive. Later, he learns that Darth Vader was aware of the Vong’s existence and the Empire was planning to use their fleet to attack the Vong in their home. This convinces Ben that his grandfather was braver than his uncle and that the Sith and Empire are the only way to save the galaxy.
Of course, over the course of the trilogy Ben realizes his wrongs, and that while Vader, the Sith, and the Empire might be efficient at war, this doesn’t justify the atrocities they commit and their overall corruption towards power. They never were altruistic and by the trilogy’s end, Rey convinces Ben to turn back to the light.
Thrawn leads the Imperial Remnant. As the situation becomes worse the New Republic and former Empire team-up, with Thrawn being a suspicious ally for most of the trilogy. However, after the final battle, Thrawn and Imperial High Command would try to betray the Republic, only for the Stormtroopers, inspired by Finn, to refuse and arrest them.
Rey is a nobody. The Jedi Order is alive but spread across the galaxy. However, Luke has still disappeared to Ach-To, where he blames himself for failing Ben and has a similar plot arc as TLJ.
After Luke’s death, Luke tells Rey to complete her training on Mandalore (inspired by Jaina and Boba). She meets with the now-isolationist Mandalorians, tired of so much war, but their leader (could be Bo-Katan, Din, or Boba, but tbh I’d prefer an OC) nonetheless relent. Rey tries to get them to fight but they refuse, at the final battle when all is lost they swoop in and save the day.
I don’t care much about keeping the OT Trio alive. They had their time, now let’s let the new characters lead. Han dies either in the first scene or before the movie starts, and this is what motivates Ben to hate the Vong in the first place. Leia sacrifices herself when the Vong conquer Coruscant.