A player during practice that is a talented receiver will be passing the ball really close to the net (almost to the other side) but when the setter is shorter, he will be struggling to do a good set to the choosed zone. The receivers during practice will pass balls that are going to the out, but they should not do it because they will also try to pass balls that are going out of the court during the game. The players on the net during practice touch the net just for fun thinking that during the game they will be avoiding touching the net. That's a LIE, of course they will be making the same mistake during the game if they do them during practice.. and what's more they will be doing them at the end of the set during an important game. This will definitely don't make you happy. Hands, legs, reactions, mind... every part of the body will remember all the right and wrong moves and touches with the ball. If the players will make them regularly for a long period of time during practices, that long period of time it will take to take away those bad habits.
"The mind will do what you teach her to do"