You're only capable of connecting one of the two cameras to the SX80's camera control port, as both cameras use the serial port for camera control.
The PrecisionHD 12x cameras doesn't support ethernet control, the network port on the back of the camera is only used for firmware upgrades whenever the camera is unable to be connected directly to the codec.
The SX80 doesn't support daisy chaining cameras using the serial camera control port. The cameras in your attached image is a SpeakerTrack 60 which consists of two Precision 60 cameras working together (identified by the box around the two cameras) and a third Precision 60 camera, al are connected to the SX80 by ethernet. If you have several Precision 60 cameras, you can connect a network switch to either network port #2 or #3 of the SX80 and connect the cameras to it, the network switch shouldn't have DHCP enabled as the cameras will pull an IP address from the SX80's internal DHCP.
What is the max. number of Precision 60 cameras that can be connected to an SX80? I have 6 cameras needing to be controlled.