Biology is one thing. However we know that with modern technology women can easily bear children into their 40s. Yes, I'm aware of the increased health complications.The Tomassian myth I refer to is that:
1. Women's only value to society is bearing and raising offspring, therefore, women not between the ages of 18-25 (peak fertility) are effectively worthless to men.
2. Men who have achieved peak social status have earned their right to mate with women between the ages of 18-25 and should only target that age cohort for dating.
The Tomassian myth isn't explicitly given by Rollo in RM (although he clearly lays the groundwork for the more toxic spins on red pill), it's the red pill interpretation that's very often given here on SS. "Men shouldn't marry, women hit the wall, hotter girls turn 18 every day, 90 year olds can still knock up sorority girls, why close that door?" etc.
For 85% of men, the door to 18-25 women closes after 35. For 95% of men, it's closed after 40.
I might bump it up to 18-30. A century ago I'd agree with 18-25.