were most likely intended as standard, “pong” type paddle controllers?
Internally, they have only one pair of wires each; power and an input, which would mean they could only include the rotating knob, and not even a fire button to go with it. The two signal leads are hand-soldered to the hand controller ports; internally, with one signal wire going to each player. These ports could never be used to add two more full hand controllers; there simply are not enough wires there to do it.
