If you question the accuracy of the sticker or whether you'd be overweight or not I'd recomend taking the truck to the scales BEFORE you purchase it. My truck has about the same cargo rating but 1800 lb less GVW so I'd definitely want to scale it to see what is going on. Why would a truck with nearly a ton more GVW have the same cargo capacity as mine? Is the truck really that heavy eating up the difference or is something else going on? Subtract the truck's weight from GVW and that's what you have left for your camper, other gear and other people etc. Also, I've never seen a vehicle with a full tank of fuel on a test drive so take that in to consideration as well!
By weighing before you buy you'll know what you have as far as weight capacity before you spend a bunch of money for the wrong truck. If it's not what you need you can move on to the next truck without wasting any money. If you absolutely have to be under GVW then at least you'll know where you stand weight wise with the truck before dropping lots of $$$. You can decide on whether you need a bigger truck, a smaller camper or perhaps you'll find you will be fine hauling an AF 1150.
I bought the wrong truck first and ended up wasting money getting into a more capable truck so I understand the decision you are having to make. Honestly you won't have any problem carrying the 1150 or 1140 on the truck you mentioned but depending on how heavy the truck is initially you may come close to the 14,000 lb GVW with an 1150. Many people (I for one) carry that camper on an even lesser truck, I wish I had the money for a new 14,000 GVW truck but my truck handles the weight really well.
My GVW is 12,200 lbs and I am over that all the time. I am under my axle weights by several hundred pounds though. All I have done for suspension mods are a set of home-made stable-loads and it handles great for me. I take it into some pretty rough country as well so I know Arctic Fox is very well constucted to handle what I do to it but along with that strong durable construction comes the extra weight.
Regardless of what all the brochures, pamphlets, websites, salesmen etc that you are studying are claiming for weights I can tell you the 1150 will weigh well over 5000 lbs when you load it up with full tanks, all your gear and take it camping. How much over 5000 lbs depends on how much gear you take as well as how many other people and all their extra gear and supplies you take with you. You could travel with empty tanks if you can get water at your destination and save 500 lbs to possibly stay under 5000 lbs while traveling but getting water where you are going may not always be an option so it's better to figure your weights full.
Northwood's advertising can be tricky if you don't read the fine print. I don't believe they are being deceptive but rather competitive in a very competitive niche market where weight means everything. You do however need to understand what you are getting, as well as what options you want to add and then add all the extra weights to the base dry weight to get a somewhat close approximation of total weight. This is where it can be confusing at first.
I do agree that they could word their Fox Value Pack brochure description better by saying it is a "mandatory bundle of high value features not included in the dry weight calculation" rather than a saying "a mandatory option bundle" where, when the average consumer reads "mandatory option", it makes it sound like an oxymoron.
Anyway the correct WET weight of a current 1150 is 4519 lbs before you add any popular options and any personal camping gear/supplies.
1150 Dry weight 3358
Fox Value Pack 595
61 gal fresh water 506
Propane 60
Total wet weight 4519
Now you can take that 4519 wet weight and add to it the weights of any other popular options you may like to have such as a battery (or 2), air conditioning, built in push button electric start LP generator, solar, dually jack brackets, TV, bunk, Fox landing bumper etc. You can see you're quickly approaching 2.5 tons before even adding any food to the fridge and cupboards or any personal items at all.
My truck (2005 Ram Quad-cab, dually, diesel 4x4) weighs about 8100 with me in it. I generally go over the scales at 13,200 -13,300 by my self which makes the camper and all it's gear with full tanks weigh about 5100 - 5200. The highest weight I've recorded was 14,050 with everything full, 2 adults, 2 kids, supplies for a week, Honda 2000 generator, 5 gal gasoline, 3 bicycles, and all my gold panning equipment. With just 2 adults and normal camping gear I'd figure 5500 lbs with my TC. Mine has AC, built in LP generator, 2 batteries, and dually brackets as options for your comparison. So you can see at times you could be approaching 3 tons extra weight on your truck, and what if you decide to tow?
Well I hope this helps with your decision. Arctic Fox is an excellent camper, I know you'd be happy with one. I would have no hesitation telling someone they'd be fine with the 2013 F350 you mention for hauling it either with stable-loads likely being the only needed modification. That said, I know some people absolutely have to be under GVW (rather than just being under both axle ratings like me) so it's best to find out how much the truck weighs first so you can do the math because as you've seen I have been over 14,000 with mine and I'd bet my old 6 cyl short cab truck weighs less than that shiny new V-8 crew cab you're looking at, then again maybe not? Good luck with your shopping.