The problem is elsewhere,
In North Bihar DBG-MFP are biggest stations follwed by SPJ-SHC-BJU.
The demand is very very high specially for good fast and on time running trains so SF is obvious choice.
Another problem is all the 4 SF originating from North Bihar 3 have good RL quota at GKP and 1 have for CPR
Now...
more... GKP also needs another Delhi train ( coming soon many be ),
All this makes situation grim.
Solution is:
Give GKP a Tri-Weekly SF for Delhi
Reduce GKP RL Quota after that
Run another Daily SF from BJU/DBG via RXL_NKE_GKP for Delhi.
Otherwise such demands no matter how wired they appear will come again n again.