When it first arrived well over a decade ago, the Pathfinder Armada used the Titan pickup truck as its foundation to become Nissan's rugged full-sized SUV. And now for its 2nd act, the Armada takes a page from the Infiniti playbook, clearly gleaning inspiration from the luxurious QX80.When I first saw it in person at last year’s Chicago Auto Show, I thought for a moment that Nissan had driven out …