After noticing several others commenting on the "trailer is level"(I missed that on the first go round apparently). After hooking up and the truck settles about 1 3/4" in the rear, as they have mentioned, you may be fine. That should put the top of the ball, pretty close to 17 1/2"...yes?
When you get the bars adjusted properly, I'd expect the front of the truck to come down a bit, and the back of the truck raise from where it is now as weight carrying is shifted onto the steering axle, and the the trailer axles, until the trailer and truck are both sitting reasonably level.
Or, when the bars are loaded, does the front of the trailer raise too much?
If all of that happens, but after loading the bars on the WDH, the front of the trailer comes up more than you want, than yes, you'd probably want the other taller draw bar to allow you to lower the coupling height, after everything is connected. As I mentioned before, ideally, you want the trailer weight to bear equally on each trailer axle so all four tires share the load.
I had a struggle with mine, but my resting height on my 4x4 with the RAS was higher to start with than yours is. When the WDH setup on mine was loaded, I couldn't get the nose of the trailer low enough, without the extra adjustment in the drawbar.
Hopefully some of this rambling makes sense.