A friend of mine, familar with the Chinese language and Southern China, also couldn't figure out how Ong could be a Chinese name until he ran into some relatives of Femon Ong. The relatives spelled their name Huang. The it would would be easy to mispronounce hwaang as ong and standard pinyin really wasn't applicable, especially those speaking Cantonese.
"Its better to build bridges rather than dig holes but occasionally you have to dig a few holes to build the foundation of a strong bridge."
"Traditional Northern Chinese Martial Arts are all Sons of the Same Mother," Liu Yun Qiao