The more I read, the more I realize that I just got lucky. I knew nothing at all about this last September when I bought my TT and F-150. All I knew was that our Honda Ridgeline was loaded as much as I would want towing our popup, and that it wouldn't be enough to pull the new TT.
I bought the F-150 with tow package not knowing anything about all of the GVW numbers required, but I also knew just from general knowledge that it shouldn't have any trouble with a TT as small as the X213 (5500 gross). Fortunately I was right and we aren't even close to the limits for the TV. Otherwise I'd be the one wringing my hands saying "Woe is me!" and looking for support here.
So I have some idea what the people who post these threads are going through, and I can commiserate with them. Stay away from the limits and you can get away with some fudging. Match a TT and TV right at their limits and you will be constantly adjusting loads to keep your axles within their safety limits, and at times you won't be able to keep them safe no matter what you do.