Inspired is probable more accurate
Yes, the Russian's developed the first full flow staged combustion engine and oxygen rich pre-burners, but that's like saying the engine in a 2023 Dodge Ram was "borrowed" from Nicolaus Otto. Different design, different fuel, different materials, etc etc etc. The Raptor and RD-270 are very different engines (beyond using the same combustion cycle). Just like the current Merlin is very different from FASTRAC