Did any boxer ever do a Curt Hennig "Mister Perfect" type thing as a publicity stunt? (I would think such antics would fit right into the late 19th century/early 20th clime where showmanship was king and braggadocio rampant) Or enjoy even middling success in any team sports (after starting out in boxing, before transitioning to something else) à la Bo Jackson?
So anybody can have Antonio Margarito like stamina by just training hard? No it doesn't work that way. Elite stamina is something that is both god given and trained for.
This is where semantics are going to start tripping people up. There's "athleticism" in terms of "quality possessed by athletes, typically" and there's "athleticism" in terms of what is meant to be understood by that in the context of boxing.
Jackson had more chances to fight longer distances and fought so many more times. But to each his own. No way to really measure something like this. I could just be thinking about stamina.
Athletic traits are normally considered those that are not teachable or able to be developed. Endurance is highly trainable, strength is also although less so. Quickness, kinetic awareness, coordination and adaptability are more or less in born and cannot be taught
I can and have taught folks to jump higher and farther and drastically improve their times on sprints, fast twitch stuff all of it. Just like endurance or stamina training, it only works to a certain point. You could never make a sub 4 minute miler from someone who was not of one of the tiny percentile meant to be a sub 4 minute miler. One can no more make a 10.0 100 meter guy than one can make a 27 minute 10000 meter guy than one can make an 8 meter long jumper. As far as innate athleticism, they are entirely equal.
You are right and they are all just pieces of the athletic puzzle. As far as them being equal components, were going to have to agree to disagree there