Well you have a point. There are faster trains between DHN - RNC .. Ideally Shatabdi could have been the fastest. But remember the Time Table plays an important role in the schedules. There could be a busy time period and it would be difficult to give a free run to any train during that time. Shatabdi runs during the busy day time so may be. Anyways, this CRP - DHN Section is facing closure danger due to mines /caving issue so we will have to wait and watch for the new route and TT.