I have to take some time to explain this. I too (Everyone) wish(s) that your proposed trains be introduced but do you know what the problem is ? I am not just taking about SCR this goes up with Indian Railways, the problem is IR doesn't have enough tracks, according to a national survey which I briefed a month ago I came across the stats that said the IR tracks have been used so extensively that they have crossed their factor of safety. In Europe the tracks are replaced even before they reach their final stage of service, but here in our country we have used the tracks to such an extent that in this period of the time tracks could have been replaced 2 times in Europe.
The...
more... other point to take note on is doubling/tripling of tracks, while there is a need of independent or dedicated freight route. If IR introduces new trains without constructing new lines/doubling/tripling/repairing of rails it will just increase the level of saturation on the tracks, then there will be delaying of trains.
For example, suppose that there are 50 trains (1 train each half an hour) running between Nizamabad and Secunderabad, and there is only partial doubling of tracks at some sections, then every train has to halt at a certain station to clear the signal for the other moving trains. Also consider that there are only 5 halts between NZB and SC. This causes higher delay.
Coming to you point of diverting some trains between NZB and PDPL, this will happen for sure but may take some time.