If you shift SER to RNC you get RNC,TATA,BKSC under one roof but you still don't get DHN, JSME, MDP etc.
And I personally I don't feel any of the Calcutta based zones have given Jharkhand any problem. Rather they have always supported RNC & TATA.
The reason for majority of projects been delayed is due to ECR's 'huge ego'. You see, when you get more than what you deserve it happens.
HJP...
more... has a huge ego and focuses only on PNBE while neglecting it's biggest bread earner DHN. Proper funds are never channelized, that is the major reason while the projects in Jharkhand are running so back-dated. That is because almost all of the new lines based in Jharkhand are being built by RNC/DHN division in unison, and they usually tend to disagree! That causes delay.
So rather shifting SER to RNC it would be much better if the railway board gets the two biggest fishes (DHN/RNC) in a same pond.
Bring all of Jharkhand in a single zone and majority of the problems plaguing Jharkhand could be gradually wiped away.