If your trailer and any WD hitch is properly set up, it won't ever sway anyway (short of the emergency maneuvers such as what CamperLifer described). The truck anti-sway relief system won't ever activate and everybody is happy. If something happens to take you out of control and sway starts, it's there to help.
As far as one system fighting the other, I think that's just idle internet conjecture. There is nothing in the way the two things operate that conflicts in any way.
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL