First, LeMond's Gitanes were built long in the top tube, with slack seat tube, so where his saddle was on the seatpost didn't matter much. He sat behind KOPS like many riders coached by Cyrille Guimard. I don't think KOPS played into what they were doing, but it's a reference point most of us understand. I'd heard Guimard believed getting behind the cranks resulted in more power using the larger gears and lower cadences he favored. Longer cranks and wider handlebars were also part of the formula, plus the low, flat back that was achieved more through forward reach than the downward reach that is favored to today. The bars were still significantly lower than the saddles.

Greg is a pretty average-sized guy, perhaps broader in the chest and shoulders than your typical skinny climbing specialist. Anquetil, also average-sized, also used 175 mm cranks, at least for time trials, and achieved an aero position through reaching lower and farther forward.

Meckx's saddle placement probably depended ultimately on how his back and pelvis were behaving, but the photos I've seen indicate pretty neutral position, maybe a little toward the back, using 73 degree seat tubes. It's a little hard to tell where the center is on a Cinelli saddle. Most seatposts of the period had a couple centimeters of setback.

We had an extended discussion here on setback a couple years ago, where we generally agreed that setback should be based more on balance than where the knee is, and that a lower position (if you're so inclined) can be made more comfortable by adjusting the balance and using more saddle setback.

If I haven't indicated yet, I have no idea how today's pros ride with extremely low handlebars and zero-setback seatposts. My intuition is that the best balance between aerodynamics, balance, comfort, and power was during the the LeMond era. Well, maybe with slightly shorter cranks, higher cadences, and slightly narrower handlebars.

Looking at this photo, you can't say this guy didn't have his bike dialed.