Something is definitely funny with Goyle. He's able to do martial arts, is extremely good with a broomstick, and doesn't trust Draco when Draco lies to him. At first, my interpretation was just that Goyle was much more capable in this version. That's still a possibility, but I feel like if that were the case then maybe Crabbe also would have been made more capable. I feel as though Goyle will do something important soon, definitely.

I even briefly entertained the possibility that Goyle was a Mary Sue, for about ten seconds, but that idea doesn't have anything to recommend it besides the humor of it.