To me, Jocks are Scotsmen; freshmen are not women, but chase them; and I've no idea what a sophomore is except through third hand context derived from TV and Hollywood.
So it is, that all three of the terms you differentiate, are simply youthful Americanisms who's meanings I derive only through inference from the media. Vaguely insulting terms used by one adolecent tribe to describe members of another. Generally interchangable.
I was a fairly competent gymnast, and I can still turn a handspring or cartwheel at will, despite my advancing years. Though the fear getting it wrong is an ever stronger deterant from proving that these days. I was also pretty good at Softball for the couple of years I had the opportunity to play.
I would never ascribe myself as belonging to any of those tribes or sub-tribes. But then, I actively shun labels, and any form of categorisation. For myself or others.
I recognise common traits in pairs or more of people, but also differences. And the latter have always intrigued me more than the former.