Billy Hamilton's speed is what made him good in track. It is what made him good in football. It is part of what makes him good in baseball. Take away Hamilton's insane speed and make him just a fast runner (let's say he is just as fast as Didi Gregorius, who is an above-average runner), does anyone really think he is some elite athlete? Don't get me wrong, he is a very good athlete, but as an athlete from top to bottom, he doesn't stand out among the field aside from his pure speed. He doesn't have a good arm, he has an average arm. He doesn't have outstanding bat speed, he has solid bat speed. He doesn't have good hands, he has average hands. He doesn't have average strength, he has below average strength. I just don't see it guys, not to the point where he is some super athlete among other top end of the spectrum athletes.
Doug, think of the agility needed to play basketball well. Think of the hand-eye needed to learn switch-hitting at the professional level after playing baseball only one season a year in a relatively uncompetitive high school environment.

Remember, too, that he is playing the most demanding defensive position on the diamond (that doesn't require squatting).

Your contention that Hamilton is succeeding primarily because of his speed is a vast underestimation of his abilities as an athlete.