I didn’t write that we should do things exactly the same as the Avos, just like I dont think we should live in tents, travel on camels, live without bathrooms or refrigeration, etc. I did point out Ma’ase Avos Siman L’Banim – we’re supposed to learn from the actions of the Avos how to act; all the Avos married girls younger then they were – not older. Yosef married a girl younger than himself, as did Moshe, Aharon – I can go on and on, straight through Tanach. We’re any of Dovid’s 18 wives older than him? Do you know of a Tana or Amorah that married an older girl – how about from the Geonim or Rishonim?
We know the historical jewish trend – you can go to a jewish cemetery in europe – in many cases the couples are buried side by side, and in some cases the husband in front of the wife – you can see when they were born and died. A random sampling of the population is the best way to get an accurate picture. If you go, you will see the overwhelming majority, is the husband older than than the wife. You can also go through geni.com, where many multi-generational jewish families are listed – again you’ll see the overwhelming majority is the husband older than the wife going back hundred’s of years.
The germans (ym”s) kept pretty meticulous records. If you’re interested in looking you’ll see the same thing. Husbands older than wives by an overwhelming margin.
I know Yocheved was born bein hachomos as you note, and I dont recall Amram in the count of the 70 who went down, so I think you are correct, but as you yourself point out – this is an exceptional case.