Of course, there's a need for mobile artillery and rocket launchers and SPH and MGS form an important element in this strategy. But there's only as much you can do about Towed guns like FH77, Dhanush and M777 if the aim is to fire and scoot to avoid triangulation by enemy WLRs and incoming fire.
I mean how far and how fast can they move on their own power and it's not really practical to use helis and trucks to tow away each and every gun to evade enemy fire- how so ever light it may be.
These guns will have to stay a little behind the frontlines and launch a massive salvo on enemy lines to suppress enough enemy systems, while the mobile artillery (Vajra and the planned MGS) and MBRLs follow/accompany the tanks and the BMPs as they surge ahead.
Again, I am no expert, so any explanation of IA's artillery doctrine would be most welcome.