They are representig your country's cricketing talents, and to a lesser extent your country's culture and traditions and standards of behaviour. They aren't representing the country's education system or ability to speak English...
Expecting all international cricketers to speak english is like expecting all national footballers to know english. If an Angolan international footballer is playing on an Angolan domestic side, chances are he won't have a need for English on a day to day basis... same as a Lankan player who trains in Madras has more use for tamil than english.
Just as ice hockey or baseball players come to the US from the non-english world and develop english as needed.
So you would rather pick people who cannot play cricket aswell as others just because they can speak English.
I think that anyone who's willing to leave their own country for a holiday or in this case, a tour should speak at least basic english.