They are "first cousins once removed" meaning that Su is the child of one of Huang's cousins. Or put another way, one of Huang's grandparents is one of Su's great-grandparents.
Also my understanding of many Asian cultures is they tend to have a much more tight-knit large family structure. And doubling that is the fact they're 2 heads of world-level hardware tech companies.
And, well, there's no such thing as coincidences. Having all of this line up, and for "some reason" AMD keeps missing when they could have owned a big chunk of the market has a certain family oligopoly smell to me.
Combinatorial mathematics actually says certain types of coincidence happen more often than we seem to expect intuitively (eg. the Birthday "Paradox").
I have no particular view on AMD. But any argument that includes "I don't believe in coincidences" should probably be weakened in your estimation.
A meteor or some natural phenomenon can be a coincidence. But especially so in industry, especially the same industry... with the respective CEOs as family, i wholeheartedly reject "coincidences".
The C word that should be used instead is "conspiracy".