What are you talking about? That way more women than men had children is a fact
That was not the point. The point is that in 30 generations you have a huge amount of ancestors:
Take 3 generations (parents, grandparents and greatgrandparents)
1st generation: 2 ancestors
2nd generation: 4 ancestors
3rd generation: 8 ancestors
Totaling gives 2+4+8=14
So each generation consists of 2^g where g is the generation number. When you put in 30 you get around a billion. However that is assuming each ancestor is unique. And that is not the case, since it would require the world population to be way over 1 billion 30 generations ago. This discrepancy is caused by the fact that people will turn up multiple times in your ancestry. Ie Charles II of Spain had only half of his 6 generations above him as unique (iirc 34 in stead of 2^6=64). I think that this is what you are trying to refer to.
However your total ancestors is the sum of all generations and then corrected for doubles (let's call it the Habsburg correction: H). So that with 30 generations you are again at around that 1 billion number.