Staff/the staff - AmE vs BrE?

[Ola Swensson]

Hello!
Could you tell me please why we tend to use "staff" without the definite article even if we speak about the staff of one specific company? I came across this use several times in my Cambridge English Student's Book.
Unfortunately, I can't find other threads on the topic in this forum, even though I think they might exist.
But I've found a thread in another forum: https://forum.wordreference.com/threads/be-on-staff-on-the-staff.634203/ which seems to suggest that there is a difference between AmE and BrE in this case.
Is that right?
Thank you in advance.

 

[tedmc]

The definite article is generally required. It is omitted in informal situations, as in "on staff", when it should have been "on the staff".

 

[PeterCW]

As a native BrE speaker I would never say "on staff".

 

[Piscean]

In BrE, staff is frequently used without a definite article when it means 'members of staff'. It is usually followed by a plural verb.

Staff, like police, cattle and crew, is normally treated as a plural noun in BrE. They cannot be preceded by an indefinite article.

 

[Ola Swensson]

Thank you for your answers!