Seeing that one can easily get confirmed seats on Shatabdi even at 1 day notice, VB with 2 extra chair cars can run full only in absence of Shatabdi.
Both can't be parallel as it will take a big dent on Occupancy for both trains ..
SR...
more... should replace Shatabdi with VB rake and the Shatabdi rake may be used to run a Triweekly Day time Shatabdi Service to Hyderabad