ELS is controlled by TRS departement, a part of Electrical department, who would report to CEE in WCR not NR.
Station has got nothing much to do with it.
the issue here is of loco allocation, about which i know less than you :P
the only plausible scenario is that IR had different objectives in mind when they set up TKD and GZB ELS,...
more... although this can only be cleared by someone who has knowledge of that area