The Russian boosters and early ICBMs were clusters of clusters. Like I said, they couldn't build a big motor, so they used a an existing design, just building a bunch. The Saturen used a few BIG engines. Five F-1s in the first stage, five J-2s in the second (and one J-2 in the third). The Vostok vehicle used a bunch of small ones. Five clusters of 4 engines each in the first stage, with the center four also function as the 1/2 stage similar to the US Atlas, which dropped the outside two engines IIRC the Vostok lanch vehicle (derived from the R-7/SS-6 ICBM) dropped the outside 4 clusters of 4 engines each.
The R-7/SS-6 was originally to have a single engine per cluster, but then the required payload weight was raised from 3,000 kg to 5,500 kg, because that's the size of the thermonuclear weapon they could build.
” Like I said, they couldn’t build a big motor, so they used a an existing design, just building a bunch.”
So ?
Saying they “couldn’t” makes no sense - if they had something that did the job cheaper, why bother ?
Did we wait until we could launch the shuttle on one big engine without boosters ? ... No ... it would be stupid to do so
NOW, they have no money, but they can launch those old rockets to re-supply when we can’t ...