1) The question here is not about what I know. The question is what you know and what you have been trying to tell all of us from a pretty long time.
2) It is quite easy to link up RSA but by doing so the locomotive do not change all of a sudden to TATA WAM-4.
3) Passenger trains do not have any fixed loco link. Plus if you are speaking exclusively about TATA WAM-4, many times it gets swapped with the one from ASN Shed.