AH reads: staff, n. A group of assistants to a manager, executive, or other person in authority.
Four staff moves at Vanquish Recruitment.
What is the meaning of "four staff" in the headline above:
Four groups of assistants to a manager moves ...
Four staff members move(s) at Vanquish Recruitment.
If that means 2 case, is the 's' needed to inflect the verb 'move'? If not, why is the 's' used in the above headline.
Also, since 'staff' in a not countable noun, is it correct to say 'four staff'?