That is a very good idea. I do however, recommend you give everything a try. In other words, if your instructor wants you to study something, you should try it.
Ultimately, with time, when you fight, you will notice that you have your "favorite teachniques". Most expert fighters have two or three throws that they do best.
I dont think anyone no matter how experienced, can do all 67 throws equal. So for your belt progression, you should try as much as possible, while keeping in mind that you will put effort into throws you are most comfortable with.
I just passed my blue belt test, and had to know throws that I never use, because they are not great for larger men. But I still studied them and showed that I understand that theory behind them. As I advance in Judo, I might even forget them, because I am focusing on throws that I am comfortable with (like uchi mata, o soto guri).