This is just a fun thought experiment, so I'm not saying that I believe AF/BB or even that women have dualistic mating strategies. However, I think that I would be much more likely to believe it if RP simply reversed the order from AF/BB to BB/AF.

Now I know AF/BB probably wasn't meant to be sequential anyways. Perhaps it is just listed that way because A comes before B in the alphabet. However, it is often described as women chasing alphas in their youth, and then settling with beta bucks when they approach the wall. This doesn't make sense to me for a few reasons.

If we pretend that sex results in pregnancy (as was more likely to happen in our not-so-distance past) AF/BB would be a very risky strategy for women. She'd get pregnant by an alpha, but not have the resources or protection to raise the child. There is no guarantee that BB will come along and save her. We already know that women have an aversion to being pumped and dumped. This instinct still persists today, despite there being no real threat of pregnancy for the modern woman on birth control. It would be very strange if women evolved to avoid any possible pregnancy external to a relationship, but also sought this as a part of their sexual strategy. It makes much more sense that women would seek BB first, secure resources, and then find an AF to make babies doped with good genes.

To support this, I want to claim that women think about getting married very early. Much earlier than men. They also get married younger than men, and look for serious long term relationships even in junior high. They also are more likely to report a desire to turn casual sex into a serious relationship. I think this is because they are trying to get a 'BB' as fast as possible. They want to secure the future for any children that might come along. It is only after the woman secures the beta that the alphas even begin to look attractive to her at all.

I want to take this further by saying that it is actually men who want play the field when they are younger, then eventually settle down once they get older. For them, it really is 'AF' then 'BB', because they want to have as much sex and variety as possible before they get married. Perhaps much of the frustration seen in TRP is from them missing out on this valued sexual phase of life for men. They know they have limited opportunity to sleep around with young women before they are forced by social norms or environment to settle down. This also fits with the cultural trope of marriage being a loss of freedom for men, but a happy relief for women.

It also makes more sense that men, and not women, would fuel hookup culture. It's men that like casual sex. There are also less men in college than women, so this gives them a slight advantage. I believe they use this advantage to have as much casual sex as possible, and women can either put out or go home. Women are sluts because they are forced to compete in a market that is unfavorable to them.