Tongue Weight Question

I know this has been answered in several threads, and I concluded that WDH does not really reduce the tongue weight.

I have a 2015 Nissan Xterra with Towing package (max 5,000 lb. and max 500 lb. hitch weight). Here's the list of trailers I've been looking at. These are all dry weight (trailer weight/hitch weight).
1. Little Guy T@B S Maxx (1670lb/155lb)
2. R-Pod RP172 (2,128 lb/244lb)
3. Jayco Jay Flight SLX 154 BH (3,200lb/280lb)

After adding a propane (they all take single propane) and a battery and some stuff, I was thinking I would have to add another 150 lb to the hitch weight.
I have not yet weigh the vehicle with full tank of gas and passengers, so this is just my guess, but the GVW will be close to or over 5,000lb. Xterra's GVWR is 5,400lb, so my actual max hitch weight will be around 400lb.

I went to four different dealers and talked to at least 5 different sales people, and they all said "you do not have to worry about (the max) hitch weight because you will be using an WDH." I started believing what they were saying until I read about WDH on this forum or other places. It looks like WDH would add extra weight on the hitch (so it's going to be worse??)...

I will go weigh my Xterra sometime this week and find out exact max tongue weight it can handle, but it looks like Jayco is out of my choice if I want to be on the safe side.

Why all the sale people say the same thing about hitch weight? They're just saying that so they can sell a trailer?

Please let me know if I'm going to the wrong direction...

Thanks,

Jiro

Work the math backwards. Use 13 percent as the target goal for the tongue weight as a percentage of the trailer's total weight and use 75 pounds or so for the WDH weight. If you have a 5000 pound tow rating for the Xterra and a 500 pound max tongue/hitch weight you can tow a trailer that weighs about 3500 pounds plus the WDH weight (3500 pounds X .13 equals about 450 pounds plus the hitch weight of around 75 pounds pretty much uses up all your capacity.) A WDH redistributes about 20-25 percent of the redistributed weight to the trailer axles so you should be good to go at that trailer and tongue weight.

Sales people are there to make sales. To make it work for you with what you have. Nuff said!