Hasn't Klimov recently criticized the Pantsir-M for being unable to defend 22800's in bad weather due to limitations of mm radars? There are apparently though differing opinions on whether the Pantsirs have only mm radars or also have cm radar capability. Regarding 20380's and 20385's, even with all the Paket limitations, they each can still carry a mix of 8 torpedoes. And the 20385's have Kalibr VLS, are they not capable of carrying and operating the Kalibr anti-sub missiles? About retrofitting early versions of 20380's, it may simply be more expedient to just build more, including the 20385 variant.