That is correct. That is how it plays on a real Lynx.
Arcade = 2 joysticks. Left joystick controls movement. Right joystick controls fire direction.
Lynx = D-Pad controls movement. You auto fire continuously. Button 1 rotates auto fire counter clockwise. Button 2 rotates clockwise.
5200 = Player one d-pad controls movement. Player 2 d-pad controls fire direction.
7800 = D-Pad controls movement. Button 1 and Button 2 both fire forward.
Play Robotron