Regarding a separate RM or whether current RM is the best or not I don't have an opinion yet. But regarding some of the issues IR is facing you can't totally put the blame on him like frequent train delays, increasing AC coaches to increase revenue as for these even previous govts. should be blamed for not forecasting future rise in traffic due to growing economy and increasing fares gradually in proportion to rise in per capita income.
However I would blame the current govt. and not just the RM for the following:
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Overcrowding in trains across the classes and for this reduction in AC classes is not the cause because even in trains with 10 LHB SL coaches the problem persists just like in trains with 2 SL coaches. Solutions to this can be more RPF, reducing WL allowed, reserving UR as 2S like in long distance trains, automatic closing doors, punishing the IR staff who take bribes and allow the crowd.
2. Running dedicated VB trains and complicating the already complicated train categories. I'm not against the concept of VB trainsets but I feel rather than running them as dedicated trains instead existing Shatabdi and Jan Shatabdi trains should have been upgraded to VB trainsets and merged in a single category. Also running VB on KR single line route where a JS and Tejas already exists is a bad decision as non premium trains are already not running on time coz of single line and rather they should have increased frequency of overcrowded M/E trains on KR. One senior IRI member (whom I have blocked now) berated me when I said Goa doesn't need any new train to Mumbai but needs to other parts of India, by saying he knows Goa more than me as he frequently instead of me born and brought up in Goa.
3. Train mishaps as the CAG report clearly stated in many accident cases proper maintenance and regular inspections were not carried out.

But current govt. do deserve credit for finally realizing the fact that current rail network is oversaturated and even in future the demand will rise and taking up projects like DFCs, doubling, tripling, new lines, etc. Also they do deserve the credit for increasing the pace of LHB conversion of trains which was horrible under the UPA regime. Also in may sections MPS upgrades to 130kph may not have yielded results now but may in future when the routes become less saturated when things like DFCs come up in across India.

Also regarding replacing SL coaches with AC coaches that was a great initiative but badly implemented later when the started to reduce SL coaches to just 2 and with poor crowd management it became worse.
They should have stuck to the previous rake standardization policy of 9/10 AC coaches, 7 SL and 3 GS plus one SLR and implemented it only in long distance trains initially depending on the demographics the trains serve also pricing 3E fares around 25 to 30% less than 3A would have seen many SL class passengers willingly upgrading to 3E rather than being forced to.