Good post Sean and valid points but hwere are a few things you must also realize when speaking of training....The older guys used natural mathods to build strength....EG you will be stronger using freeweight than nautilis ( however you spell it)....ever notice how the strong man guys rarely use those type methods...Same with running on all terrain rather than a treadmill...todays guys have supplements that help out though...todays methods are ment for faster results..
Also..look at glove size? Type of gloves ect when factoring how they would compare in the ring...guys like robinson,,,Bassilio,,,LaMotta..Louis ect had amazing stamina and ability to stay in and fight...if they had the modern methods to build them up faster and supplements to go with it they would have been twice what they were also...CC on the topic