I started doing a little research on the Armadas and here's some conclusions I have made (IMHO).
- The Armada has a pretty short wheelbase for a 27" trailer - this doesn't help your situation
- The Armada has a fairly low payload capacity. I'm going to guess that the sticker on your Armada says somewhere in the realm of 1500lbs for payload. Lets say you have 4 passengers at 150lbs each - that's 600lbs. Lets assume your TT is 7000lbs with a tongue weight of 1050lbs. Thats a combined 1650lbs of payload that is over what your truck is rated for. That doesn't include ANY other gear inside the vehicle.
- I'm willing to bet the rear end sags with that kind of weight which is going to cause some sway
- You haven't mentioned whether or not your using a weight distributing hitch (I really hope you are) that may or may not have sway control on it.
The problem is that someone is going to tell you that your Armada will tow it fine because all they know is that an Armada with the towing package can tow 9000lbs but they aren't taking payload into consideration.
This is just my opinion - there are others on this board with much more knowledge than me but I think you are already at or over your max for that Armada.
Edit: Also, I'd suggest "E" load tires with that setup and when you're towing I'd at least have the rears aired up to their max cold PSI.