not only that, let's be real here. the language barrier isn't that big of an advantage, especially for defensemen. at the end of the day, you're still playing the same game.
gus can learn from timonen on a different line. it's too dangerous IMO to have 2 small defensemen on the same line. you start getting into playoff games and playing against bigger teams, smaller defenders just get pushed off the puck too easily. and as well and consistent as timonen has been, he's getting older, and a little weaker, and he isn't able to shield off forwards as well as he used to.
besides, the main point is that the top 4 of pronger, carle, timonen, and coburn have been playing with each other for a while now. they have chemistry with each other. pronger brings out the absolute best in carle. on any other line, carle would not be the same. if it ain't broke, don't fix it.