I thought that Sangha got EMD from SBC to MAS because of E-Loco shortage - few years ago. Have seen many Freights too from JTJ side coming with UBL EMDs at WFD, due to shortage of E-locos.
WDP4 - was curious if it was used for Vaigai for its high speed capability. Else thought why not some Alco from GOC or ED.