I'm sorry but I have to fully agree with you here pc1 again!

If you excuse me. We're not twins but we may very well have twin impressions on certain topics.
What you're saying here is a thought that's never left me. The sheer job of only facing the absolute best, day in day out, maybe almost a 100 times a year (imagine Borg-Mac 79, 80, 81 going out only on a heavy-duty H2H worldwide tour or Federer and Nadal... Woaw!) seems to me incomprehensibly tough. Your worst nemesis -- each and every day, the fiercest opposition imaginable. I can't really say I have a full understanding of how difficult that really is but IMO it may contend for the toughest task in tennis as we know it.
So when everybody else just flushed the fields with easier prey -- with the Open Era from 1968 onwards -- some comfy down-time arrived and the GOATS Rodman and Kenny got the breathing space for a whole, dang slew of laser-engraving seasons on the planets trophies and winner-rolls far into the Open Era. This absolute tennis steel-bath is IMO another major factor that must not be dismissed or forgotten when the level of "The Apex Predators In Tennis History" is discussed either in conjuction with earlier or later players or just within their own era. With a repeated underlining of own because that's what these players just did aided by their seemingly unlimited greatness...
If some magnificently deranged scientist who's an underrated genius with regards to quantum-physics invented a time-machine tomorrow and -- generously just for me of course -- created a three year time-span where we pitted the perfect hornet's nest containing Björn, Rodney, Kenny, Ricardo, Roger, Rafa, Ivan, Jimmy, Mac, Pete, Andre, William Tatem and all the others "Apex Tennis Predators Of All Time" and even including the ones with the slightest suspicion of that rooftop tier -- all in their maximum form -- it wouldn't actually shock me one bit if the before 70s bunch would whip so much azz it would look like a prolonged comedy-routine. If it were so that Ken and Rod would blowout Borg of 76 and 78 I would still be slightly surprised but I would nod in agreement. I suspected something like that could possibly happen.
Now I don't believe this to be the actual case if the whole time-machine shebang came to reality -- but the sublime perf's by the older than 1970s bunch are quite simply astonishing and not the easiest to measure in comparisons...
But it has definitely planted a seriously healthy seed of possibility that this scenario has a hefty shot at being truthful. I also see other contrasting scenarios (though they don't include any fast court blowout losses for players before 1970 won by the younger bunch) also...
There's also this fact that if you play a months-long H2H tour with your strongest foe you get the finest practice there ever will be. Talk about honing your skills. Practicing endlessly how to motivate yourself and regroup effectively to turn around a dangerously weak patch of humiliating matches, which could have more serious consequences than a cracked and weakened psyche -- your wallet was on the line -- acute monetary anorexia -- just ask Gonzales -- regardless how great you once were. And they played such diverse circumstances, forced tirelessly to adapt to new and not seldom extremely inferior courts with comically abysmal lighting.
A seriously hard-knocks lifestyle. Which enhances the greatness of Gonzales and the other 50s and 60s guys enormously in my book.
Just a side-point -- I'm soon done with my Doherty study. It's quite big. Too big. But I feel satisfied. Now there's a lot of info I'm going to research in the year to come during travels and such -- but I got a heft load of stats, breakdowns, analysis and a bunch of quite interesting new and more detailed info regarding the many mysteries that surrounds a lot about them...
I'll think I'll start a new The Dohertys-thread and post in installments so that I can live a life too -- what do you think pc1?