A rover is like a swiss army knife. You wouldn't want to have to chop a cord of wood with it, but in a pinch, it can do anything. The Rover is a jack of all trades, but a master of none. If you are hauling horses regularly on our fast highways, you should probably get the master.
While they will tow adequately, and even nicely, it's simply another thing they can do, not a primary function. For everyday towing, get something that was designed for it.
I tow with my Disco, and fairly regularly. I have towed some very heavy loads, but I'm not fooling myself. A pickup is better for heavy towing on our roads.
Cheers,
Kennith