In the past 100 years, Chinese restaurant owners have been able to hire unilingual Chinese waiters who are able to serve clients in Chinese restaurants across the country. How can they serve their clients? By numbering the menu. New waiters, even though they had recently arrived from China and spoke neither English nor French, were able to count up to 100. And as the menus were produced in order to help people who could speak almost no English or French, those new waiters could serve their clients.
I think that if we had the same approach to client services, it would be possible for people who are unable to hold a conversation in French to offer services all the same.