That's not really a good benchmark to use here... A dually with a fiver in tow is going to be stable at full rated load and beyond, because it's a dually, specifically designed for hauling and towing heavy loads, and it's pulling a fiver. A Ranger, like any shorter wheelbase, midsize truck or SUV, is basically a compromise, because the manufacturers know they are going to be used mostly as daily drivers and grocery getters, with only occasional forays into the world of towing significant loads. Once you hitch up and tow with the Ranger, you will probably be much less impressed with it's capabilities than the manufacturer's numbers suggest. You won't be unsafe, but it's not going to be as carefree as using your F-250. JMHO, based on having towed with a midsized vehicle. Wheelbase makes a significant difference.
YMMV. Enjoy your new camper.