I think he means with how Spence is rugged and can be a brute when need be, is how he'd want AJ to fight as a HW.
The issue is that Spence has shown a better punch resistance than AJ. He can take shots better imo
Well either way it's a pointless comparison.
Welterweight is entirely different to heavyweight and vice versa. Let's not even get into zone thresholds, primary energy systems at different sizes/weights and mass vs non mass aerobic/anaerobic output capacities.
Joshua fwiw, has had one fight (perhaps two if we count the Klitschko fight) where he was badly concussed and/or showed the affects of concussion.
Ruiz threw not only a perfectly weighted lead hook to the temple in that fight, he threw a perfectly weighted lead hook to the temple with his 'best punch' that he has in his arsenal. Ruiz is exceptional with the lead hook, not exceptional at a whole lot else for the most part.
For a heavyweight this is far from an indication that he has a bad 'punch resistance'. It's heavyweights, they're all a millisecond off a brutal knockout at all times.
'Most people don't know.....' - Roger Mayweather.