Every player of any billiard game stands a bit to a lot different.3C players tend to be more upright and snooker players tend to be quite low. I think a better question than when is why. What are the advantages and disadvantages of very low vs. more upright that lead to the 3c/snooker difference in stance height? Visual, stroke mechanics, something else?
A good example is watching professional baseball players at the plate.
Some look pretty conventional and some look just odd.
But it works for them.