The best way to counter a chinese/eu/na team that has korean players

Use strategies that force the enemy to make decisions, especially when immediate response/timing is key. Anyone can win lane or do their job in teamfights or play their champion well. But when you force situations on the enemy that requires well timed , concise communication, the language barrier can hurt them. Of course, you need to make sure that you're not getting outclassed on the basic things like individual skill.