Their reproductive system being wholly evolved and lacking any technological elements could work well.

Cloning on it's own for a galactic level civilisation would be a bit of a no-brainer so it needn't be connected to Gungans as a narrative component.

I bolted it on so that the Naboo conflict could be called a Clone War (and to give Jar-Jar a slightly better origin story).

The one technological aspect that the Naboo could be guardians of is the Gungan's accelerated learning and growth.

Natural accelerated physical growth is also very plausible (on Earth very few species have childhoods as long as ours) but accelerated learning would be tricky to put down to some sort of biological mechanism.

Unless the Gungans are strong enough in the Force to be born knowledgable. Which would make them an obvious target for Jedi and Sith alike.