it makes more sense in judo since all countries are supposed to use the japanese names for the throws. seems harder with BJJ since you have multiple language transitions followed by eddie bravo giving a name to every damn minute position you could possibly get into. add into that people using names from wrestling and sambo, and you've got so many language transitions that stuff is bound the get tricky. for example, scott sonnon has an entire dvd on mastering the saddle position, which is just a derivative of the 50/50 guard (i guess in sambo they call the 50/50 the side saddle or something).
the isolated club nomenclature is also considerable. my own experience with the "genie armbar" is a small example, but apparently this is what caused the whole switch from "brabo" choke to "darce" choke. i can't remember the story correctly, but basically nobody was brabo choking much for many years, and then a guy comes into a high level club and chokes everybody out with it. they start referring to the choke after that guy, and then the choke becomes big in tournaments, so everybody calls it the darce choke now.