Dear P' Tim,
Since, we are working at native English speak company which is yours company. Personally, I strongly believe that we do need to use English as possible as we can for communicating to USA team.
In my opinion. they are good at their work or I can call some of then as a genius over geniuses. However, they could not explored their ideas in the way of English directly.
Moreover, this is a magnificent opportunity to experiences English for both general speaking and advice purpose in their workplace.
I truly appreciate the chance to be English classes.
Tan