No it isn't, it's saying they DO have the natural ability the same as the modern fighter but that natural ability alone does not make them a champion.

Fighting comes natural to some and they make the best natural boxers but "boxing" is anything but natural and proficiency only comes with endless hours, days and years of practice. No matter how good one is "naturally" they are not going to become a professional boxer unless they are trained like they are.

In the olden days it was perfectly acceptable to go for a jog, do some sparring and hit a bag for awhile in between ridiculous fight schedules. Unfortunately in todays landscape it takes a little bit more than that to be successful.

In fact, it take a LOT fucking more!