Roy won't knock Willard out, & he won't be able to go 45 rounds either. Just depends how long he can go before dropping from exhaustion.
OK, your points are (A) that the weigh in rules have become more liberal, and (B) that fighters can add lean muscle mass more effectively today. So how important are these points? A. A guy who can make 175lbs at the age of 37, without cutting a limb off, is not going to be a big heavyweight in any era. B. I really don't know how much bulking up has helped smaller heavyweights.
I will concede a but at b we are working with unknowns here. I honestly don't know either but at a certain point we are debating the philosophy of modern boxing. Is bigger better? Not for everyone obviously, but we all act like it is. I think it was very important for Byrd because it helped his punch resistance and kept him from getting manhandled as he would had he fought at say 185. I think Byrd thought the same thing. Whether he was right is debatable. To your larger point here size is extremely important if the combatants are relatively close in skill. I would take Mickey Walker over Butterbean and i will take Roy over Willard (although hell if i know he can do that for 45 rounds). But Mickey Walker against Joe Frazier? Thats not happening. Roy Jones against Mike Tyson? Roy would be lucky to have all his limbs. Willie Pep and Pernell Whitaker are consider the best pure boxers of their generation. I think 9 out of 10 of us would pick Whitaker and we would need no more justification than Whitaker is bigger. You are an old school boxing fan janitor. What's that old axiom: a good big man beats a good little man.
No way in the world is Roy knocking Willard out! I think Roy is struggling even to land very consistently on Willard to any great extent? There was a common theme from Willard filmed fights against Jack Johnson, Frank Moran, Jack Dempsey, Floyd Johnson and Luis Firpo - in the open long range boxing exchanges no one was really able to land effectively enough to get anywhere near to having been able to say they outboxed him even. Very similar to Vlad Klits Willard looked an absolute nightmare to fight just like Vlad people looked to be struggling to get past his arms and his continual holding and he did fight very tall just like Vlad possibly more so - and he would lean back and away from shots that were even getting through - really awkward!? His own lol range punching worked for him too and he was pretty quick fisted at his peak - certainly matched Johnson when they threw simultaneously and also pretty well matched Johnson in terms of his own ability to feint and anticipate which was Jones' bag too. To be fair for whatever reason for all intents and purposes it looked to me that the only way to actually beat Willard was to stop him?. And unless you could hit like a truck that didn't look possible - cereal you not at his peak? Johnson didn't really hurt him particularly in 26 rounds and he hit a helluva lot harder than Roy - I'd dare say Moran hit harder, one punch than Jones too and he couldn't really register on Willard - and Jesus Roy didn't really like Ruiz hitting him too often?? If Willard gets a hold of him and gets him with any of those uppercuts - Didn't Willard killed one guy almost by accident??
or you are imagining elephants roy was massivley faster than johnson and attacked in a differtent way. He isn't getting a 1 shot ko but to say he can't get a stoppage is pretty short sighted imo, and to use old jack johnson as the comparison is just wrong. vlad is also a poor comparison to willard, although a lot better than jones/johnson.
Roy isn't stupid. He wouldn't be firing all cylinders for a bout scheduled for 45 whopping rounds. It's not particularly hard to imagine him reining everything back and lasting 12, 15, maybe 20 rounds. Dangerous, untested waters await him past 20, though. 45 might be a bank too far.
Are you going to try to argue that marathon runners don't have good stamina, because they are slower than sprinters?