Paul2004
Some aircraft, and they are in the majority for the company I work for, only indicate conflicting traffic within15NM around and within 7000'.
About flying into a/c ahead, we are all cleared on arrivals into FACT with speed restriction at specific points. If one a/c is catching up with the one ahead, and he has not reached the decel points, it is your job as ATC to slow him down or speed the other one up! Just maybe the guy in the back is not aware of the closing speed.
You are the controller- now control boet!