Dak
mentat
What makes them top, and what's the science that supports it? What does top even mean? How much they enjoy themselves, their social status within a certain sphere, their psychological stability, physical health, financial stability, surveys of what women think "top" means?
Generally speaking it's going to be a confluence of genetic leg up (height, attractiveness), combined with or socioeconomic success, or the success alone. Usually the qualities that allow for success are present regardless, and are what launch one into success in respective areas. Discussing "success" can get very complicated, but attractiveness really isn't. I would assume you heard about this:
http://blog.okcupid.com/index.php/your-looks-and-online-dating/
As you can see from the gray line, women rate an incredible 80% of guys as worse-looking than medium.
I don't agree with everything the guy says, but I'm not about to attribute it to whatever beta stuff since he trashes the thinking that anyone is "better" than anyone else. One quote from the book is something like "real men don't concern themselves with what makes them real men to other people."
The first sentence and the second sentence do not go together. "Real men don't concern themselves with what makes them real men" because they are already doing what makes them "real men" - and therefore being better (usually). Insecurities flow from various deficiencies or at least unmet potential, whether actual or merely cultural. If you think many people are better than you, you're probably right - just maybe not about what thing they are better at/in/etc is. Everyone is better than many other people at something. Some people are better at many things than many people.
The points you made about the necessity of men I find solid, but I don't see how the fact that women can have penis envy cancels out men having womb envy. I think both exist.
If womb envy exists outside of transsexuals this is the first I've heard of it, and I've seen no supporting data for it, official or anecdotal.