Splitting up people based on being able to speak english or not?
Sounds like a bad idea.
If someone is unable to speak english he will probably stick with people who can speak RU, same on the other way arround.
Also considering this to be an old patch, most PVE content can be done without the need of comunication,same with PVP since you can simply follow marks.
If RU people or ENG people have problem with each other,simply avoid plaing with certain kind of players.
Talking about language privilege in instances, i can get that, but "banning" people because of language barrier it's kinda racist, if the person is capable of doing dps and following,i don't see any problem,you just being a dick (for both partys).
As i said,comunication is optional,it's faster yes,but only RST require more cooperation,the others are just follow 1 players and marks.
Everyone at this point should know about SWB (i forget most part of it,but youtube it's always there with video guide) and it's mechanics,back when i used to lead it, nobody was speaking inside TS to avoid miscomunication, a couple of marks was enough to always reach Rank S.