The glaring problem with this strategy is that 99% of the most marriageable women will already be married or engaged by the age of 25 to guys from their own age cohort. Contrary to popular belief in some corners of the manosphere, the vast majority of high-value young women are not sitting around at age 20 hoping to marry a 35 or 40 year old guy. Do you know why? Because they are already dating a guy approximately their own age from their social circle. High value women are essentially never single, especially in their prime. They have too many options and unless you have an eight-figure net worth and/or some kind of fame/status, your chances of convincing one of these girls to marry you when you're already pushing middle age are slim to none. That's the reality of it.
Does that mean a 35 year old can't marry a 20 year old? Absolutely not. It just means that a 35 year old is not going to marry a high value 20 year old. And to clarify, high value in this context could be defined as a girl who is attractive, intelligent, not sexually promiscuous, emotionally stable, comes from a good family environment and who is interested in starting a family in her 20s. There are not a ton of those girls to go around, and the guys who are fortunate enough to date one of them as a young man usually realize their good fortune (or are clued in on it by their older relatives) and marry her within a few years. If you think you're going to just live in some sort of monk mode until you're 30 and then effortlessly court and woo high value young women, you're delusional.
If you want a good wife to start a family with, your best bet is to meet her when you're both as young as possible. There are really no exceptions to this rule. Do not think that you need to spend a decade "working on your career" or otherwise perfecting yourself as much as possible in order to find a good woman. A good woman is not going to somehow distract you from your professional ambitions. If anything, having a good woman in one's life universally makes men better in that regard. You're more disciplined, more responsible, harder working. The much bigger danger to most young men these days is wasting your twenties chasing meaningless sex and playing video games. And then you wake up at 30 and realize it's time to settle down and you're left with the dregs and rejects of the dating pool. The leftover women, who are leftover for a reason. The prime women were already scooped up in their high school and college years, and the next-best were engaged by their mid-20s. "But scorpion," you say, "It's fine. I know that. I'm just going to marry one of those younger girls, not one of the used up, damaged ones who spent the last decade getting pumped and dumped." Well good luck. You're gonna need it. Because it doesn't happen very often. The best you're likely to do is settling for a girl without kids who recently came out of a long relationship/marriage. And that's a whole other kind of baggage to deal with.
In the end the matter is simple. Your odds of finding a good, high-value wife are much higher among 20 year olds than 30 year olds. And the reality is that it is much easier to date a 20 year old girl as a 20-22 year old man than it is as a 30-40 year old man. The social and logistical advantages of being younger simply far outweigh the financial and experiential advantages of age in this case. If you want to start a family, find a good woman and find her early.