Antenna switching 2 each 4 way switch boxes

I'm using now A Denkovi USB relay board with eight channels connected to my 6600 USB Bit cable to auto switch one 4 way antenna relay box . This has been working great for the past few years .

I'm wanting to add a second 4 way antenna relay box to were the first box in the shack will send RF to the second box on the tower . I'm posting a picture to help explain . In the picture I show a wire from the control board tower relay to the tower port in the shack .. I know that's not correct . What I'm thinking may work is to add a second wire from the control board 160, 60 and 10-20 to the Tower port in the shack .

I think I need 3 steering diodes but I'm not sure where to put them and in what direction ?

The picture will most likely make more sense then me

Am I on the right track ? is their a better way ?

Thanks Ed N5DG