In Judo there are hundreds of different throwing techniques and manoeuvres and students in the early months of training hope to learn a new one every week or so.
Some teachers refuse, and tell then to keep practising away at just a couple.
Other teachers do in fact demonstrate many different tricks. The fact is that however many tricks a student may have in his repertoire, he will not be able to do any of them, because he has no balance. While he is making the moves which are designed to upset the opponent he begins to be upset himself. Sometimes he loses his balance so completely when trying to do a complicated movement at speed that he even falls over. In both cases the student thinks he is learning technique but in fact he is learning balance.