I do realize the equipment was quite different in those days
The " lag load " imo is when the weight of the head of the club is lagging behind the initial movement of the hands and arms when loading into the backswing.
For me it helps with the rhythm and tempo. Give it a try .
P.S. Nice quote !
Years ago, beginner sets were sold with 1w, 3w, 5,7,9,pw, and putter. Maybe a sw. Why did we move on? We wanted to get better. I understand (I think) the whole retro thing... Guys playing hickory shafts, persimmon woods, which they never hit well, and their half full bags. But in my mind there is a caricature of that person. Faded everything, from the bucket cap to the cardigan and khakis. They love to tell you about every club in their bag, which barrel they picked it out of, how little it cost, and how they would gladly replace them, if they could only find something they hit better. This won't happen, because their swing speed is under 70mph. They were all "way better ball strikers" when they were young, yet they are the only former scratch players turned 20+caps most will ever meet. They never buy balls, they "find all they'll ever need in the woods, lol, nod, wink". I could go on and on...