Use Your Brain. WR has P5 shed at BRC which is Beyond Ghat section and Almost in North India Cluster. There there is no issues relating to Soil Profile and Level Of Banking of the tracks. In ER there is only a single ELS is Recognised which is HWH and has all kinds of technical bars to start from. Say If ER was Till MGS then MGS may have gotten it by now but it isn't like that. There are Whole lot of Technicalities about locos it isn't easy like you think that "Isko P7 mila usko kyu nahi mila.Sdah Raj P7 pe Duronto kyu nahi ".