Most athletes are single-focused. When they try to do more advanced sports than what they’re used to, it often doesn’t work. See Herb “I can run fast” Washington. Likewise, when multi-talents go against specialists, unless the physical difference is vast, they can’t compete. But there’s a few who’ve gone the distance. Take Bob Hayes, gold medal sprinter, Super Bowl champion and Pro Football Hall of Famer. Or Mariusz Pudzianowski , a Polish weightlifter and strongman-who became a champion mixed martial artist.
This is of course not true for everyone. Most sprinters couldn’t be wide receivers. Most weightlifters couldn’t handle actual fighting. But there are always outliers like those two. There’s also an interesting number of legendary hockey/soccer crossover players like Lev Yashin (hockey, famous in soccer) and Vsevolod Bobrov (soccer, famous in hockey)
What would be interesting would be multi-sport stars who aren’t physical outliers with an obvious advantage (ie Bo Jackson) or people who can take advantage of playing in a similar sport (some Caribbean baseball players who also played cricket growing up).