Let the numbers make the determination as to whether or not you need a WDH. The OEM for your vehicle has already done a whole lot more calculations than any of us here have. If the trailer's tongue weight falls into the range for a WDH per the TV's OEM, then get one.
I have gone against the grain of the forums before. We had a Coleman popup that tipped the scales at just shy of 3700lbs. (3300 on the axle, a little less than 400 on the tongue). My F150 ratings do not call for a WDH unless the tongue weight is more than 500lbs. I never had an issue. We did have one instance of uncomfortable sway (on the freeway, heavy cross-winds, semi passing us to windward side) but a touch of the trailer brakes brought everything right back in line. (Added another 1/2 turn on the friction sway control and never had another issue like that again)
