And if you need a brush that is even closer to "broad, flat brush with spotty texture inside" it get's a bit more advanced:
The basic idea is to use half the dabs (or more) to build a second (or more) brush that gets combined into the first. The caveat in this special case: Eraser erases everything, not just the newest stroke. But this can be prevented with layers.
Here is that brush as a zip that can be imported in myPaint and will show up as "SpottedBrush" group, so you can look at and modify those settings. Also note the notes.
Oh and I forgot, if you have the tumagonx built from here:
You can use "Angular Offset 2" (aka Angular Mirrored) with Random to get a broad stroke of small dabs, without the falloff from Jitter...
Oh, well there is also the option to use a smooth broad brush first and then go over it with a spotty eraser to add texture...