NGMV is mainy aimed towards Pakistan that as they will be well suited to take care of strike duties so that destroyers from the Western Naval Command can be freed up to tackle the looming Chinese threat.
Why do you even need some 2500ish ton ships for that role. They should have gone something like Korean Navy Youn-Youngha class Patrol ship which costs some 50M$ without Missiles. The koreans built this with exact same threat scenario as ours, i.e a rogue nuclear power state with Missile Boats.
Comparision: Youn-Youngha class vs NGMV(From Wiki)
1. Tonnage: 600 vs 2200
2. Cost : 56M$(Inflation Adjusted) vs 220M$
3. Speed : 44-Knots vs 35-Knots
4. Armament : Provision for 2* Quad SSM/LACM Launcher(Presently 4xAShCM) vs 8xBrahmos
If they want dedicated Missile Boat then 2200 tons is too wasteful. Leave aside 600 tons, just that touted ASWSWC tonnage nearing 900 tons vessel is perfect for that role. You got speed in form of WARP for near 1000 tons which is ideal. If the goal is to have a fleet of distributed arsenal with cooperative engagement capability then you need more than 6. If they had halved budget to 100M$ for each ship then they would have 12 such ships which is think makes more sense.
Or my analysis is wrong that Navy would also use these ships for General purpose role like recent Houthi conflicts where fielding our top tier destroyers too overkill and leave gaps for vulnerability in vital areas.