I think that "na-SCHE-li" may be trying to represent the original pronunciation of the name in the Zapotec language, but that is not how most modern name bearers would pronounce it. They would use a "Hispanicized" pronounciation that would end up sounding like "nah-YELL-ee", "nuh-YELL-ee" or "nye-ELL-ee" to English speakers.
It's like "Xochitl". The original Nahuatl (Aztec) pronunciation of that was "show-CHEAT-ul", but in modern Mexico it usually is just said "SO-chee".