no, of course they were not the best athletes necessarily. some of them could play some facet of baseball well but could not do anything else in athletics. the same is true for the football players i coached.
probably the best athlete i personally coached was a football player at McCallum named Tarron Brooks. Ask Mark about him.
After my junior year, both our coaches left for greener pastures, and were eventually replaced by a couple of our assistant football coaches. They liked baseball, but they tried to coach it like football (which I was still playing at the time, as well.) The first two weeks of spring practice, we hardly picked up a glove or a ball, much less swung a bat. They had us out there running karioke drills (I think they were called), airplanes, up-downs, things like that.
We'd gone to regionals the year before and had several returning starters and several more who had experience off the bench. But I guess we looked kind of scrawny to our coaches; so they went over to football and recruited several of those guys. I don't think it took much - football was going through their own spring drills at the time, which were
brutal. Several of our starters were benched in favor of the new arrivals.
We sucked in pre-district, winning maybe 1/3 of our games, but by district the criticism of the coaching was so heavy that they reverted back to starting the better baseball players. We didn't win the district or anything, but we were at least respectable after that.
One of my fondest memories of all that was after the football guys came over, the coaches installed our all-district nose tackle in RF. He was about 5' 7" tall, and nearly as wide. Perfect for a NT; but he couldn't run for shit, couldn't track balls, and he threw like -- I would say a girl, but that would be insulting to girls. He threw like a sissy. Couldn't swing, either; he had zero flexibility. The guy had always been kind of a bully in school, but he got so frustrated with baseball he actually cried on the field, during a game, after screwing up a pop fly for the umpteenth time.
That ended his career as a bully, and for the most part ended the talk that football players were better athletes.
I don't know which sport has the best athletes. If you'd asked me at the time, I would probably have said track. Specifically, the guys who ran the 880 (or whatever the metric equivalent is). I tried that event for awhile, and it nearly killed me. I couldn't ever figure out whether it was a sprint all the way, or if one should pace oneself for awhile. I usually ended up sprinting the whole way, and the last 200 yards always felt like my legs were operating according to some plan other than my own, and that my lungs were about to burst and come out through my nose, or ears, or both.