Do you mean a tow dolly? The bugeye's gonna run about (i'm guessing) 1500 lbs. Mine is listed (kerb weight) at 1900, and that's with huge bumpers, etc. The dimensions are: less than 11'8" long, 4'8" wide. Typical tongue weight on a trailer is 10% of the trailer's weight. With a tow dolly, it's gonna be next to nothing.
The ranger can pull it, for sure, but what is the ball rated at? I mean, the in-bumper ones are not as secure as a reese-style receiver. A class 3 hitch w/ 2 5/16" ball can handle roughly 8000 lbs. The 1 7/8" or 2" balls (and lesser hitch) can handle somewhat less, but still at least double the weight of a bugeye.
In my experience with UHaul (when I brought mine home), they were the most incompetent people I've ever dealt with, concerning towing. Don't take their advice, just use their equipment. We rented a tow dolly, and specifically asked if the 2 5/16" ball (for the horse trailer) was ok for their dolly (because we have a 1 7/8" ball for the sailboat as well). "Yeah, it's fine." When we get there ... sure enough, it has to be 1 7/8" or 2" and we have to buy it from them, because it's not worth the hassle of going back to get it.
Now, the 'gentleman' who installs the ball on the hitch installs it upside down (like one would do for a car, even though we have a full sized chevy truck). Naturally, I told him that was incorrect, but he said, "you need the extra height." Whatever. Sure enough, when we put the tow dolly on, it's way too high. Forget it, it's adequate. If I was towing my car trailer, the back end would have dragged on flat surfaces with it set up like that!
Don't get me wrong, the company provides a service and they do it well (before anyone gets excited). I am not bashing the company! However, I've found that the help they hire (managers included) are the next best thing to incompetent. If you want trailer advice, talk to a shop that does RV's and trailers, not the folks to work at UHaul.