Star Wars civilizations only inhabit 1 galaxy, and 2 smaller cousin galaxies, one of them is the rishi maze. The other galaxy is where the chiss originate from and there is very little lore about it. The yuuzhan vong also come from another galaxy, but there is no lore about theirs either. So it doesn't matter that star wars has multiple galaxies when 2 of them are extremely small, and we barely know anything about 2 of them.