Agreed, but that is why carrying extra weight sometimes is not a good thing, extra power sure, but it is wise to use what got you to the big dance in the first place, if it is not broke, do not try to fix it.
If you're serious about making this a "what if" instead of a fantasy fight, it would make more sense to put it in 62/63, when it was a genuine possibility. Both were top contenders and Liston suggested that Johansson should have to win an eliminator against Williams to earn a title shot.
After being sparked twice by Floyd and later floored by London , to be saved by the final bell, I don't think Ingo would be very enthusiastic about facing Williams.
If this is in 62-63, assuming they don't adapt their training differently which is still a big assumption. We still have Big Cat in a 209-213 range with Ingo ending his career around 200-201 lbs. As little as 8 and 13 lbs between them at the most. This still isn't very significant at HW, especially with Big Cat being a slightly taller guy. At this point regardless of weight, Ingo was pretty done after Patterson 3 while Williams was hitting his stride. I think Big Cat is a cautious favorite here.
Extra weight doesn't seem to add punching power as we've seen guys like Evander never develop KO power no matter how much muscle they added, but it does help with physical strength and just being harder to move. Weight is weight. Moorer for instance would have been rag dolled and worn out at 180 lbs by some of the men he fought, but at even a chubby 220 or however much be weighed, he was able to hang without getting too worn down.
Agreed, carrying extra weight can cause a fighter to get winded, especially if he has stamina issues, I guess a fighter has to find a happy medium.
In all honestly… this is the absolute truth. Poor Williams. Big tough guy. …But Not cut out for beating champions.