i disagree with your coach.The best player can hit hard without miss.Only two way to get it. First way, hit hard and miss a lot in the beginning, little by little, you will improve and reduce the miss. In this way, you challenge and you win. you are excited and interested. Then you play more and improve more.
Second way,you play like a student.You do what coach told you.Even you win, you can not feel that kind of feeling like Way 1,little by little you will lost interest, then game over. Even you do not lost interesting, you play in this way for a long term,and you can not improve your strength and you can not give your enemy more pression, then your enemy attack you more. Attack is the best form of defence. If you disagree, please see Peter VS Andrew.
All in all, we are amateurs. Interest is the best coach