Agreed. All schools focus on three areas -- Standup (throws and locks), groundwork (chokes, locks, and hold-downs), and self defense. Depending on the school, they may emphasize one area over the other. Schools that are "sport" oriented tend to spend less time on the self-defense aspect. While they spend time on both groundwork and standup, usually they'll devote more time to one vs. the other -- often the one the teacher is best at. "Combat Judo" schools and their ilk spend more time on self-defense, as they tend to de-emphasize the competition component.
Kosen Judo practiced at some of the universities in Japan I've been told varies from the standard Judo curriculum. I've never witnessed it but they apparently emphasize on newaza (ground fighting).
Just a guess here, but considering that Kosen was supposedly the style of judo/jujutsu taught to the Gracies, I would think that the Kosen techniques are probably contained within the BJJ curriculum, right? I'm sure new techniques have been added since then (and you'd have to forget about the Vale Tudo techniques), but I would think that any "original" GJJ/BJJ techniques should be than equivalent to Kosen techniques.