Yep -- the encoder if ordered for a Happ joystick will come with 4 2 wire wires rather than the Sanwa type that comes with a single 5 pin wire. And on the ZD encoder there are 2 separate plugs one that has a 5-pin connector and the other is a bank of 4 2 pin connectors that are labeled Up, Down, Left, and right - So if using the Happ joystick you use the 4 2 pin wires to go to each of the microswitch NO and Ground connections and then plug into one of the 4 2 pin spots on the encoder labeled Up, Down, etc. depending on which connection it is for. And the 5 pin connection on the encoder will be left empty. (both the 5 pin joy and the bank of 4 2 pin are connected together internally on the board so you use one or the other not both - since they both give the same inputs to the system and can not be used for seperate joysticks.
The ground wire for the Happ type is separate for each direction thus each has 2 pins (one for that direction and 1 ground) where the Sanwa type has a common ground and 4 directional connections in the 5-wire plug)