I don't have any experience with brassy minnows as they are not found in the areas I have lived or visit family... From reading about them, they sound like they would adapt to pond life but prefer low gradient streams. Other links indicate they handle predation poorly which is similar to the fathead minnow. I am not sure if they would have any advantage of the fathead minnow. If you can get a large number of them for free by collecting them you can certainly take advantage of it. Be careful though, wild caught fish often carry disease and parasites and you don't want to introduce those into your pond...
