IMHO
I think it took a much more capable and well rounded driver to win races a few decades ago.
Therefore
Don Busse, Daryl Busse, Del Insko, and Bob Farrington.
These four each won national dash winning championships driving Knee Knocking, Cross Firing, and all around Bad Gaited Nickel Pickles.
Only in their later years did they get to drive Point and Go horses like Dunn and Tetrick drive regularly.
If Busse, Busse, Insko,and Farrington drove back then like Dunn and Tetrick do today with their hand holds in their belly buttons, they would be turning somersaults in the first turn not winning races.
Busse, Busse, Insko, and Farrington had to do all the tactical things of todays drivers plus concendrate more on keeping their horses upright.