If in Future VB has to replace Gatimaan, then why not do it in the first place,
Let Gatimaan be replaced from its current LHB Shatabdi rake to VB Rake and then extend it to KURJ. Gatimaan is running with a 12 coach rake out of which only 10 are for passengers and it can not be increased due to its speed, so its better to replace the rake with a 16 coacher VB rake, by this even seats will get increased and there will be no change in MPS as well, and extra seats will serve the extended portion for KURJ as well, I don't see a reason to run a extra train when already there are 2 trains with...
more... almost same fare structure running in morning. But if IR is so adamant to run VB as a new service then they should start it as a 8 coacher service, analyze the patronage and then increase coaches if required.