My opinion on VB is that these should replace existing LHB rakes of Shatabdis and incase of Mumbai Goa the Tejas one.
If slot is available increase frequency of existing trains like Goa SK, Vasco Patna SF, etc. also run these with 2 SL and 2 GS if you want. No problem.
These would generate both profits to Railways and beneficial to the common man too.