Well, of course "taller" as regards q'horses is - um - variable.... My horse was q'horse with a tiny bit of thoroughbred 4 generations previous. HE was 16.5 hands, and short backed - missing about 4 vertebra that "normal" q'horses have. Most people around here who have registered q'horses have horses in the 14.5 - 15 hand range, and were a bit shocked to find out that my paint was not only registered with the Q'horse Assn but the Paint Assn as well. I got told regularly that he was "too tall". (Well, he was in a way.... I literally had to put him in the ditch out front in order to get on him - my back and legs are just not very flexible after 65 years of life....) But there's no height restrictions on registration.... Oh.... btw.... I regularly hauled half an elk out of the backcountry on my horse. Half an elk is like half a horse - 600 pounds. So - nope. You do NOT need the plowhorse look to mount a plate-wearing toon. Of course.... this is a game, not reality any way....
QHs are amazingly versatile, it's a shame that the trend recently is towards beefy peanut rollers, long as a bus, with genetic disorders. Back in the 80's I used to event on a QH who was 16.2. 16.5 is a typo I assume? Since it only goes to 4 and that would be 17.1?
Still, really not what I would want to joust on.