I agree with you, security personnel and cleaners are of utmost importance, regardless of the number of workers or the size of the company, they must be present.
It is something I refer to in the course of the development of the topic, when you are starting and the company is not open to the public the number of staff is a minority, the less staff there is the better economically, and then to start serving the public, they must have the rest of the staff available.
These functions are performed by the director. In addition to the secretarial staff, human resources personnel are also needed at the beginning of a company.