Hey there! I'm applying to the ETA for Azerbaijan, which appears to have the same requirements as Armenia (I was also considering Armenia, but changed my mind at the last minute). I am not Azeri or Russian either, but I did take a year of Russian. However, both countries seem to want to distance themselves from Russia and are trying very hard to replace Russian with English. I read that, at least in Azerbaijan, locals would much rather speak Azeri than Russian. In other words, while Russian may be somewhat useful as you try to adapt once you're there, I don't know how much it should affect your application. At least that's my opinion. Good luck!