Aye, more like patterns. The goal is just more randomness and more spice in linework, shading etc. for a very stylistic approach.
Things like random rotation or size would also spice up the brush quite a lot! But as mentioned before: I have no idea how the technicalities look like, so sorry if I sound like a madman right now.
Thinking about it though, a lot of what I had in mind could be done with random rotation/size too if you could set the parameters. Maybe tinkering with that would prove more useful than the "random brush switch" setting?
The shorter you can set the interval the better, and since you pull the brushes from a separate file maybe transforming the brush parameters already in aseprite would be easier?