The higher their common mode rejection, the less the effect will be.

GND and signal, whatever way you wire it, will never have any common mode rejection of the actual noise sources. There is a false urban legend that "ground is ground" it is not. Also, one often overlooked fact is that when chasing such noise using the scope in anything but differential mode (B invert, A+B) will never show you what is going on.

As an example all equipment at a datacenter blew up causing several millions of dollars in damnage (I just saw the misspell, did not correct it I like "damnage") and it was found that the cause was that the datacenter and the lightning arrestor shared a ground - how is that for "injected ground noise"

Make your switch line or whatever a RS485 line and use the "industrial strength" transmitters and receivers.

Erik