I have a little different opinion here. For distances as large as 2000-2500 kms, there should be a pair of SF and non-SF trains operating where the non-SF would connect the larger stations to the smaller stations while the SF should cover up the larger stations only for faster connectivity. For e.g. HWH-ADI Express is a pretty good train for people from small towns of maybe Odisha or Maharashtra to go to any other major city of Gujarat, but for end to end passengers this train is a nightmare, though being a superfast. A faster connectivity should be given for the sake of end to end passengers.