In the sensors table, it lists two housings (hand held and wall mounted) and two sensor categories (single and array).
An array takes up [6] capacity but only the maxed out wall housing is big enough capacity 1 to 6, 6 being the capacity needed.
The sensor housing table lists the maximum sensor RATING by size of the housing.
So you can have a hand held device that caps out at 3 capacity, which means 3 single sensors. Those sensors are in turn capped by the size of the housing limiting it to rating 3 sensors.
P.446 A Large drone, cyberlimb 5, Max Sensor Functions
Motorcycle 6, Max Sensor Functions
Vehicle (larger than a motorcycle) 7, Max Sensor Functions
By this logic, drone's could not have sensor arrays.
What is insinuated is: that you can have a sensor array on a drone, or something small.
Example: P. 127 "Bounty Hunter", "sensor array (Rating 3) (handheld),"
P. 445 "Most vehicles and drones come factory-equipped with
a sensor array (at a rating listed with their stats)."
What I understand is: a single sensor, is a single sensor.
and a "sensor array", is more than one sensor in a single device. Like infrared goggles that also have low light vision. 2 sensor functions.