The security decker that is responsible for the integrity of the host where all the premises cameras, drones, sensors, weapon turrets, elevators, maglocks etc are slaved to can be located anywhere in the world and just enter the host. He will not be in an armored car outside the facility.
The security rigger that keep track on on premises cameras, drones, sensors, weapon turrets, elevators, maglocks etc can be located anywhere in the world and just enter the host to where all the on premises security devices are slaved to. It will be as if he is himself on premises. He will not be in an armored car outside the facility.
Wage Mages that are responsible for the astral protection of the facility; astral projection to patrol the premises, summoning watchers to patrol the premises, placing and keeping track of wards around and in the facility etc. can be located anywhere in the world and then simply astral project to the site. In a combat situation they could be responsible to deal with dual-natured threats and could possible even commanding a spirit to materialize to help out with mundane threats, but their main purpose is to patrol the facility from the astral. They will not be in an armored car outside the facility.
The physical on premises security force will be physically on the premises. The security force might or might not include a combat mage, but the security force -including the mage if the force have one- do this this for a living. They are not your ordinary professional rating 0 wage slaves and bureaucrats temporary reassigned for this task. This team will be physically located on premises and will coordinate together with the astral patrol and the security rigger to ensure physical safety of the facility. They don't expect special favors or luxury vans just to do their regular job. And while they theoretically all could be located in an armored van outside the facility it would leave them kinda vulnerable to be taken out all at once by a single anti-vehicle rocket....