To the people upset about how many champions are now Vastaya:
"I would theorize that the vastaya are not an individual species, but a taxonomic classification more on par with a larger order, or a phylum."
This means they can still be as different as an eagle is from a goldfish, or a human to a turtle. As all of those are of the Phylum Chordate, which includes fish, amphibians, reptiles, birds, and mammals. Nami being a Vastaya doesn't mean that she is that similar to Rengar or Xayah. It pretty much just means she is a magical animalistic humonoid, which we already knew that she was. Not much has changed.