I have seen the Cat Bus/Appa thing, though not for a while. I think it primed me to see the connection? But Appa looks like the Cat Bus!

*nods* I can explain the same language thing as a result of some past historical contingency reenforced by everyone traveling around a lot, but the lack of accent is kind of baffling. Unless we take lilacsigil's suggestion above and see the variant pronunciations as remnants of distinct accents?