Ruthenia was called Ruthenia because it was in the West, and part of the Polish-Lithuanian Empire, so went by the Latin name for Rus. Russia is derived from the Greek. Even centuries ago they were distinct.

And before then, before there were nation-states as we think of them now, the principality of Kyiv was distinct from the principality of Mosovy. Kyiv was not subordinated to Moscow until Peter, Elizabeth, and Catherine, in the 1600s and 1700s -- more than a millennium after Kyiv's founding.

The history is not made up.

https://www.timemaps.com/history/russia-979ad/