I have read through the previous questions and answers, and it still isn't clear to me what/how to submit to pass this exercise. Asset handling works nicely in 5.0 which I had been using - is that acceptable? (I tried various things using 4.0 and 4.2, but didn't manage to get any "Saved/Brushes". I did with 5.0.)
I would agree with Omar... When Draw was originally recorded, I believe it was before the current Asset Tool Shelf, so doing the brushes the way Paul did was how it was done then, but now I believe you can use the same asset management you'd use in other parts of Blender and mark it as an asset.