There is some Logic also..Bcoz The timing at which BSP rajdhani enters NDLS , it is a order or a queue of Rajdhanis. Pf allocation in Railways don't work on basis of Individual Train's Passengers convenience (AT LEAST at BIGGER Stations) , instead it works on the benefit of All. When all Rajdhani Brothers are going towards the same areas , then NR can't give any kind of Special Privilege to BSP rajdhani only.
And I said NZM can accommodate One more LHB rake , and thats bcoz in Delhi ncr region , its is not bound tot hat the terminal station of the train is always the PM area also. Many times we have seen NDLS terminating Trains going all the...
more... way to DEE near pitlines for idling. NDLS terminating trains are even sometimes seen near NZM also. NR has the convenience for sending the Rake anywhere around Delhi ncr as per the congestion increases.