Essentially Zircon will replace Onyx eventually, that is its place.
The Kh-32 is replacing the Kh-22M, but its liquid fuels are highly toxic and not popular so an air launched version of Zircon could be a fairly obvious replacement for Kh-32.
The Kh-32 is a natural evolution of an older system that externally looks the same... the difference is better liquid rocket motors and improved energy fuel.
The Kinzhal is an air launched version of the ground launched Iskander solid fuelled rocket and is a quick fix stopgap solution.
Zircon has the most potential as it will be the lightest of all these weapons, but also the fastest and probably ultimately the cheapest, because its scoops up oxygen as it moves through the air like other jet powered objects.
The solid rocket and liquid rocket models need to carry their own oxygen with them which quadruples the weight of "fuel".
Zircon will fit into all land based and ship and sub based UKSK launch tubes, and likely will be adapted to be carried by their strategic bombers and the Backfire as well and perhaps a smaller model for lighter aircraft like the Su-34 and Su-35/30.
Being jet powered it can throttle up or down to use fuel much more efficiently, so being launched from very high altitude and very high speed wont impact its performance as much as the same would with a solid rocket motor powered missile.
They will likely continue to use all three weapons, and indeed upgraded Onyx models as well because they are already paid for... and all are rather potent against a range of target types.
I would never say helpless. They have some pretty capable ships, but its unlikely they can defend against these missiles with their current defensive systems
Certainly not helpless.... in fact if they remain in port in the US I would say impervious to most Russian anti ship missiles most of the time....