If there is no bilingual staff in our department, how can we make a best use of the Company Data?

Company Plan users can also also invite bilingual staff from other departments and external suppliers to their account. 

That way a person, fluent in foreign language, can be assigned as a Translation Manager  and can register your Company Data.

Alternatively, you can place a Translation Order through YarakuZen. 

All the Phrases that are ordered will be saved in the Company Phrases regardless of the user permission types, so they can also be re-used within the company.