Dude, don't know what kind of russians you've played with, but most of players from my country speak on really low level like me-you-he-she-it etc. I'm not gonna say that theres none of them who can fluently speak however it's really exaggerated to say that 19 of 20 russians can't say a word on english. I'd rather say that their level is at the same level as polacks and other easterners. That's based on faceit/esea though, haven't played matchmaking for years.
First of all: Thanks for you answer to my thread!
I agree with your part to britians, made that experience aswell and I share your thought
To the second part: I don't say 'russian', when I don't know that he is one. I usually ask or check their profile and when there stands 'Russia', then I doubt, that they are fakeflagging