Interesting article, but I can't help think there are more variables at play you seem to be suggesting - especially in the 20+ category.
Age is a big one. If a 36 year old woman has notched up a 'kill count' of 20, then that's an average of just one guy per year since the age of 16. Obviously this is subjective but I really don't consider that particularly high. I wouldn't necessarily class a woman like that as 'wild' or difficult to tie down.
If a 21 year old girl on the other hand had slept with 20 guys, I wouldn't be surprised if she did indeed have the characteristics you outlined above.
Also, what about women who 'played the field' back in the day but now want to settle down/possibly start a family? There's plenty of women like that out there and I can't imagine they never feel emotionally attached or worry about what their partner is doing. They might not even be all that confident after years of being pumped and dumped rather than being treated as serious relationship material.
My last girlfriend (26) had by her own admission around 20 previous partners. I don't know what the real figure was but she was clearly in the 'confident/self-assured' category. She definitely did not have all of the characteristics you've listed in that category. Yes, she was sexually adventurous, but she clearly did have a strong emotional attachment to me - tears and all. I could probably have told her anything and had her believe me, despite her being highly intelligent.
It was also me who was very much 'in charge' of the relationship, even though she was a few years older than me. I don't really consider myself to be an über dominant man - although I'm flattered if you think otherwise. Obviously I don't know for sure whether she cheated on me, but all things considered it seems pretty improbable. I won't bore you with specific details, but I've got greater suspicions about some girls who rank further down the sexual experience ladder.
Not saying these categories are all bull by any means, but I'd definitely see them as just a rule of thumb rather than anything hard and fast.