Cougar says trailer GVWR is 12,500 lbs. I took 20% of that and came up with 2500 lb pin weight. Ford says the CCC for his truck is 3400 lbs. if that is correct he will be fine. In any case he is comfortable with his truck and trailer combination. IMHO there are many on this forum that think they are experts when in fact they are just weekend warriors like the rest of us. I have heard numerous folks here say "you can't have too much truck". But when I say why don't we all drive Peterbuilts or Freightliners the response I get is they are too expensive. If he comes back and says he has reevaluated the situation and says he is opting for a bigger truck, then so be it. Until then I am taking his word that he believes it is safe and he is comfortable with the combination. For those that aren't comfortable with his decision maybe you should ask for his itinerary and take an opposite route.
That Ford CCC that you are stating (in bold print above), is from some brochure or table....not the actual yellow/white sticker on HIS truck. If you read all the print in those charts, those are baseline numbers for stripped down models with the bare minimum of equipment. He has already stated that he has a Lariat, CC, 4x4, Diesel. As I stated before, my previous truck was identical, except it had LESS stuff on it than his does.....which means I had more payload than he does.....and I only had 2148 lbs. So, you might see that some of us "experts" as you call them, might know just a thing or two about his situation......especially when we've been there, done that!
My present truck, a 2016 F350 DRW CC, 4x4, King Ranch, Diesel shows 5710 for max. payload or CCC. My actual sticker on the door post is 5270 lbs. That's almost a 450 lb difference. And trust me, it's a LOT more of a difference on his truck.
We'll see, if and when he posts his actual numbers from the door sticker. His 2017 isn't going to be much different than my 2011 F250, except like I said.....he's got a Lariat and I had a XLT