Two different temperature sensors... why?

[Dllrd23]

In the 4 pin sensor, it appears that is the one used when the instrument cluster contains a coolant temp gauge. The Blue/red wires are used for the cluster signal (blue/red signal brown/orange is the analog ground). The brown/pink wire and the blue/white wires are the sending circuit for the engine computer. The 4 wire is what is called "double NTC cooling water motor temp”. The other 2 wires are on the instrument cluster diagram but they are in the same connector. Very confusing. The engine temp sensor is the engine compartment temp sensor mounted on the intake between the front 2 passenger side runners. Hope this helps.