We had a forum member a few years ago and had some handling issues with the Armada...turned out that the rear IRS suspension was out of alignment and due to rust issues couldn't be brought back into alignment.
That member upgraded to a different truck IIRC....maybe they are still active and will chime in. I can't remember the user name.
Not trying to discourage you as I think it's totally doable just make sure everything is as meticulously maintained and learn how to adjust the weight distribution hitch correctly.
Thanks!
Jeremiah