ADM2867E RS 422 Transceiver

scenario 1

I am interfacing RS-422(Isolated) channels of two systems with each other and  each system has RS-422 which have five wires i.e Tx-, Tx+,Rx-,Rx+ and Ground as show in attached diagram (File name : Both_System_ADM2867)

Q1:Did we need to connect ground (isolated) to chassis through RC filter in each system (File name: Both_System_ADM2867 with RC filters) ? is it necessary? what are the advantages and disadvantages of it? or it's work okay as it is shown in diagram( File name : Both_System_ADM2867)Kindly give reason of it .

scenario 2

I am interfacing RS-422(Isolated) channels of two systems with each other 

1) one system has RS-422 which have five wires i.e Tx-, Tx+,Rx-,Rx+ and Ground

2) Second system has RS-422 which have ffour wires i.e Tx-, Tx+,Rx-,Rx+ 

as show in attached diagram (File name : Rs 422 five wires and 4 wires)

Q2: Did we need to connect ground  to chassis through RC filter in system which has five wires  ? or with out RC filter its work okay ? Kindly give reason of it .