Its modified yakhont not moskit.Moskit has low range.
Brahmos does S-manuever in terminal stage and is also resistant to ECM.Its not just speed,its speed,kinetic energy,sea skimming ability and late stage manuevering at mach 3.
Babur is no more stealthy than say a tomahawk,subsonic missiles use sea skimming for late detection..it gives them survivability but newer SAMs can easily intercept these.A supersonic sea skimmer is much more potent.
Define 'long distance'.Because without air cover/asw escort a patrol boat out in the ocean is a sitting duck.
And brahmos is supersonic all the way making it hard to intercept at mid stage.IN already has klubs but prefered to replace klubs on talwar class with superior but costlier brahmos.
CM-400 is easy to detect and shoot down because 1)it can't perform manuevres 2)Due to High flight profile then dive its detected much earlier by radars due to no sea skimming.Its for this reason China doesn't really use this missile,its main ships use Yj-18/Yj-83.
I'm not claiming victory,i'm saying with current assets PN most probably can't stop a blockade.PN needs a air defence ship like FREMM frigate with aster instead of large numbers of patrol boats.However i agree these boats are better than azmat due to stealthy design and better missile.