I agree. Even my point is same that each time RM changes a huge difference is brought in coach patterns by way of different names. Instead railways can categorise only 4 to 5 varieties. For speed up train priorities can be localized. There are still many normal superfast trains which run with good priorities in many routes. Speeding up of train depends on LHB and track maintenance majorly in my view.
Now there is technically not much difference between Tejas and Shatabdi. So Tejas gives a branding to introduced party.