Agree, George was freakishly strong for sure with more clubbing punches, Mike was more explosive and the unseen can be devastating. There's a fallacy that the modern larger boxers would generate more power, Wilder possibly but he's only been tested against Fury, so until I see him against the other top guys in the division then his power is overrated to me. Mike and George fought the top guys in far deeper eras and brute force wasn't always sufficient to get the win. As you say it's complicated, we can only really guess based on level of competition and different styles fought, even then it;s far from conclusive.
He carried over 230 in his first career, but yes 226 he may have been fully hydrated. I do not know-you have a record of when he was how dehydrated? Certainly he was not large by modern HW standards. Because they consciously bulk up-& some use PEDs, I doubt Foreman ever did. Also you cannot merely use weight-he was leaner in his first career than many in recent times. Also if he was say 6'6" like Joshua, then considering how much these guys weigh in lean mass per inch, he would be lean in the mid 240's. Then just because the number is larger folks would think he was more bulky. So not large by modern standards, not a SHW-but even today he would have no less than average lean mass per inch. Without extraordinary weigh training or (likely) any PEDs.