"However, RDSO said EMUs have enough power to pull the rake through the ghat"
LOL, they really think it is about power??? are RDSO walah so naive to think that the coupler can survive the immense force brought about by having motive power only at the front???
what are they gonna do if the one of the traction motor fails at the rear??? in case of locos you have sufficient redundancy even if an entire bogie (3 TM's) are knocked out, in case of EMU that much redundancy does not exist and TM...
more... failure could lead to catastrophic circumstances especially when force on coupler increases drastically in a very short amount of time.