In colloquial English, "the police" can mean both "the public authority charged with maintaining order" == rendőrség, and "the people working in the police force" == rendőrök.
Consequently, a rendőrök can be translated correctly in multiple ways. All of the following are correct English:
- the police
- the police officers
- the policemen
All of these variations must be accepted as correct. If any of them are rejected, please report that as a mistake.
‘Police officers’ got rejected. Meanwhile, in normal courses, ‘policemen’ is begrudgingly accepted with a message saying it’s not appropriate to use that word anymore.
Presumably for the same reason that in English they have the word "POLICE" printed on the back of their uniforms... not "POLICEMAN".
And on a fire trick you might see "FIRE DEPARTMENT", not "FIREMAN" or "FIRE TRUCK".
It's the name of their organisation.