The Army of Chaos members are in charge of security. A number of them are permanently staying in the second villa which is hidden behind the thick forest at the back of the property. Unless someone goes there or gets an aerial view, they will not know that there is a building.
Ron approved that this can be used as a base for the Army of Chaos, and at the same time, he does not need to worry about the security. With all the gadgets Felix, Nico, and Beck installed and the Army of Chaos members present, this property is more secure than a fortress.
The staff in the house is also picked from the candidates in the Los Angeles' Boyle Heights neighborhood and they can do much more than cleaning and trimming the bushes in the garden.