Hmm.

I mean, it’s not gonna happen for other reasons (including the “Russia doesn’t have the naval and air forces to get control of the ocean required to have the ships cross it” point in the Vice article that I link to in another comment), but if we set that aside and assume a hypothetical world where Russia could get control of the sea and the air over the Pacific, I think that there’d be hypothetical ways to work around a limited number of landing ships.

The amphibious forces have to be able to seize and defend a port so that non-amphibious-assault ships get in.

So, the capacity is bounded by the time required to do a round trip to your staging point and the number of ships you have.

And there isn’t really any land nearby to use as a staging point.

But…you don’t actually have to reload at land. I mean, you could do ship-to-ship transfer, then have the landing ships do another run in from an offshore concentration of warships. If you really worked at it, you could probably get pretty good throughput.

https://en.wikipedia.org/wiki/Underway_replenishment

They also have LCACs. Those can land forces on unimproved beaches as well.

https://en.wikipedia.org/wiki/Aist-class_LCAC

https://en.wikipedia.org/wiki/Lebed-class_LCAC

https://en.wikipedia.org/wiki/Tsaplya-class_LCAC

https://en.wikipedia.org/wiki/Zubr-class_LCAC

I assume that they can launch them from Ivan Gren-class LSDs. Maybe it’s possible to load them via crane or something to increase throughput, dunno what doctrine is.

They also have some ships that can carry helicopters, and can use that for insertion from offshore.

https://en.wikipedia.org/wiki/Russian_Naval_Aviation

And they have some landing craft of other sorts than what you mentioned; see the “landing craft” section:

https://en.wikipedia.org/wiki/List_of_active_Russian_Navy_ships#Landing_craft