The Kirov, is exposed to submarines, with an helo carrier anti submarine ship like 23900, or carrier is very good, of course you can never fully defend from submarines but commander of kirov will never be stupid enough to sit still in middle of atlantic or Pacific simply disclosing his location to enemy groups.
More likely Kirov can conduct missions when enemy fleet is detected to move to a position where conducting a zircon salvo launch is possible at maximum range.
From an anti shipping perspective, the kirov with zircon alters the naval balance of power.
Submarines still dominate, but if Kirov were to stay on the move, harbored within the safety of russian waters, and in early detection of an enemy fleet move to launch position it is raining unstoppable hypersonic salvo on the entire CBG.
The areas where kirov will be sailing to conduct said launch should be reconnoitered and the ship itself presents a juicy target to enemy submarines.
But with a cunning command, the ship will present sea denial and supremacy of up to 1500km.
Zircon is not stoppable by battle order of any western navy, that's a fact. A salvo of 8 to 12 it is impossible to do a thing , with aster, sm3, sylver sm6, phalanx, goalkeeper. It is absolutely not going to detect a fully powered maneuvering cruise missile coming mach 12 at sea level.
And no zircon is not aero ballistic missile, quasiballistic missile, semi powered gliding, or maneuvering gliding missile.
It is FULLY powered missile with characteristics not fielded by any navy in the world, who can even replicate such a target. No kinzhal and even avangard do not replicate the firing solution of zircon.
So again, Kirov with 194 VLS and about 40 zircons on board is enough to level several CBGs of enemy naval forces.
This fact does not change that russia is implementing distributed lethality. But is a force multiplier of epic proportions.