It'll work fine, but watch the payload. Daughter, kids, and their stuff along with the tongue weight might push you over the payload.
It may be "crazy" to take 2 vehicles, but I think this idea is crazier. Personally I wouldn't want the hassles of setting the WD hitch up for a different vehicle for one trip. Not to mention putting in a brake controller if it doesn't have one built in, which I don't think the Armada has. And if your RAM has a built in controller, that means you'd have to buy one for the Armada.