My opinion is YES. Also, I presume you are actually asking about the weight distributing bars. The sway control is a different animal. I would have a decent weight distributing hitch with a friction sway control.
In a perfect world with a perfectly balanced trailer, a sway control should not be needed. But, we do not live in a perfect world. If you happen to get the wind from a passing truck or at a road pass, the trailer could sway and you could not recover from it.
A W/D hitch and sway control is a cheap insurance policy for safer towing.
Ken