Given that the Narns were agrarian prior to the arrival of the Centauri,
and were under their heel, and got most of their tech FROM the Centauri
leftovers, no, they're not more advanced. It's a lot like the Russian
situation, seemingly this tremendous power, but once you look deep, not as
well off as they'd like you to think.
Claudia loved the scene when I first described it to her, prior to
finishing the script. She was dying to do it, and kept sort of "doing" it
around people for some time prior to filming.