I'm a 4.5C. If I pop a ball up in a 4.5 match, I'm pretty sure someone is going to put it away against me (and vice versa).
I actually think that is the difference between 4.0-4.5. Short balls to a 4.5 are going to be played more accurately and aggressively than at 4.0. Depth with spin is very important.
Saying that when you pop a ball up you expect that someone is going to put it away is a VERY long way from saying that you haven't ever played with a 4.5 player who struggled putting balls away. You know your teammates abilities- you seriously don't know any players who struggle at the net at 4.5?