Himars could be thinner rocket on 4*4
Depends. We could, but where does it fit in with our doctrine and ORBAT? That is the question we need to ask ourselves. Do we have areas in the front that are so remote where infrastructure can't be developed to take a sub-20 ton Tatra 8X8 High Mobility Vehicle mounted Pinaka? If yes, does it make tactical sense to take an MLRS system there? Keep in mind that if we can't take Pinaka there, then that also means we likely can't take any 155mm artillery piece there either, unless by Chinook (M777 only). And if there are such areas, we had better focus on road infrastructure development there otherwise such areas will only be defended by 105mm and infantry.
As far as I can see, there would only be a handful of such areas, if at all. And only in the mountains. In such areas, would we benefit from 90km range MLRS? Immediate tactical needs would be better served by mortars. Lots of them. Interdiction can be done iva other means if MLRS can't be brought there. Such as MRPKS of Army and DAS by Air Force.
Keep in mind, the Americans named that system as HIMARS because there MLRS system was the tracked M270 MLRS. HIMARS was a lighter version mounted on a 6X6 wheeled High Mobility Vehicle mostly for the USMC. In our case, Pinaka already has that level of high mobility. Do we really need a higher level of mobility for a 90km range MLRS?
Do we have a system that can be used for area bombardment beyond 150km (maybe upto 400-500km)? I.e., it needs to be very cheap with decent accuracy which can be produced en masse. Smerch with 9M544 rockets is an example for the lower ranges of the category I mentioned and PHL-16 should be at the high end (at least non-TBM versions). Do Pralay/Prahaar etc fall into that category? AFAIK they are vertically launched systems (or can they be launched directionally?) and as far as a simpleton like me can understand, being vertically launched, they will burn more fuel for course correction and it will put at least some limitations vis-a-vis their size vs range. And that extra bit of complexity will surely add to the cost as well.
Sorry if this has been answered before.
There is Pinaka 2, a 300mm MLRS that is said to be in the works for ranges upto 150km and warhead weights of around 100kg.
Then there is Prahaar for upto 200km/250kg and Pralay for upto 500km/500kg. If mass produced, their cost wouldn't be prohibitively high.
You said PHL-16. That has got around 8 370mm rockets with a range and warhead similar to Prahaar. And the PHL-16 can also fire two TBM like American MLRS that fire ATACMS. The Chinese TBM is a 750mm missile with less range and warhead capacity than Pralay missile.
As for the disadvantage of vertical launch you mentioned, the tactical advantages outweigh them in Himalayas, where vertical launch means you can hide in defilade behind a mountain range right at the foot of the mountain, safe from counter-battery fire. Chinese PHL-16 will face this limitation that it will have to come out in the open or else its rockets won't clear the ridgeline. Compared to that, the minor increase in complexity due to a TVC and control surfaces that would otherwise still be needed to improve CEP means its an acceptable trade off for the ability to fire from defilade.
We have systems comparable to the Chinese ones. Its just that they aren't tested and deployed yet.
