The "natural" footballer (soccer) physique is far from ideal: it's basically just thick legs and very rigid back. It's only in the last 20/30 years that footballers started training the whole body, mostly because "why not" - their physios are now well-educated professionals with degrees, they're already at the gym on most days, and it helps them look cool.

This said, they are definitely closer to "ideal" natural proportions than most bodybuilders. They are also more balanced than tennis/basketball/baseball players, who have to work quite hard in the gym to compensate for the extremely unbalanced efforts their sports require.

There is a lot to be said for the rugby physique; sadly the sport is insane on the grounds of personal safety.