Yes that format worked so many times when joe louis, marciano, dempsey, tyson, sharkey were matched against 6'6'' guys atsch...
Johansson doesn't make that class though.. In fact, he was usually the bigger guy hammering smaller men, and even got KO'd twice by a fighter who by all standards would have been a cruiserweight in Cooney's era.
May give us a clue on prime Johansson vs the Cooney of the Foreman fight though. I think it's difficult to assess Cooney's prime abilities because he never got to showcase them against an opponent that could have truly gauged his class. Either he fought against overmatched/washed up opposition or he was in there against a Larry Holmes. It's been said many times before, but we sadly missed out on fights against the likes of Coetzee, Weaver, Dokes and others. It's hard to say how he compares to those fighters. Johansson was a boxer who could find you out if you did not have the ability to take it or fight according to a solid gameplan.
How can you be so sure? Patterson never defeated a ferocious prime puncher with Cooney's size, power or fast starting ability... In fact, he was lambasted by Ingo, and dropped by guys like Rademacher, Harris and Quarry.
Likewise, Cooney never, ever beat an opponent remotely similar to Floyd, or as good as Floyd. He was impressive and dominant to the likes of a past prime Young, and shot Norton & Lyle. He fought valiently vs Holmes, but once again that proved he had little to no experience against top opposition like Patterson. One thing about Patterson getting dropped is he almost always got up and in the end defeated Ingo, Quarry, Rademacher, and Harris. Cooney never came back when faced with adversity. Furthermore, Floyd's weakness was a right cross. Cooney never had that impressive of a right cross. Floyd could defend against the left for sure.
I think this is the crux of it. To be fair gerry did very well against holmes - only seasoning and championship round experience let him down against an ATG. But that is also the point - he was largly unproven before, still lost and never rebounded from it at all. Had witherspoon dropped out of sight after giving holmes such a fight could we base his worth on just one losing effort? It is a crying shame gerry never fought the rest of the lost generation. he ticked a lot of boxes in a losing effort and was better than many belt holders.
i dont understand why use the cooney from the foreman fight when the cooney from the holmes fight was clearly a better version