Mules are slightly smaller than their horse parent, and when they grow they share traits of both a donkey (the long ears), and the horse (color, tail, etc.). A Mule in the grass.
For example, a 2014 Ford F-150 is considered a half ton truck but most variants can carry a lot more than 1,000 pounds in the bed. Since these terms are probably not going away any time soon, it's best just to think of them as smaller, mediumest, and more than medium.. (Pause for laughter).
When properly equipped, the Titan XD will have a maximum payload capacity of more than 2,000 pounds and a max towing capacity of more than 12,000 pounds, making it the strongest half-ton in the segment or least-capable three-quarter-ton available, depending on how you want to define it.