Firstly, they are not accidental oddities, as there is nothing accidental in their creation. These variations occur because statistically they must occur. No accident is required.
Secondly, if someone tells me that everyone on the planet only has ten fingers and I then find out that some in our population have a different number to that - then I would say that the person who told me that you can only have ten is talking bunkum. Just because it is a rarer variation does not make it non existent.
The silliest part of this discussion is that we have got away from the main point of discussion, which was that someone said that the XX, XY should be the determination point for female or male competition. I was just trying to point out that there are certain people who would not be covered by such a determination. It would be like banning the population of Hong Kong (7.5 million) from competing in competitions around the world due to them not being the right genetic combination.